GB2423175A

GB2423175A - Payment system

Info

Publication number: GB2423175A
Application number: GB0503103A
Authority: GB
Inventors: Paul Baker
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-02-15
Filing date: 2005-02-15
Publication date: 2006-08-16
Also published as: GB0503103D0

Abstract

A system for making a payment from an account of a user is associated with a plurality of personal account numbers, which are capable of authorising payment from the account. The system comprises a payment device 2 from which one of the personal account numbers can be read. Further personal account numbers can be provided by inserting a disposable memory card (Figure 7a). When the payment device 2 needs replacing only a portion 4, retained by a screw 52, is replaced. A card reader has levers (85a, 85b, Figure 10) which are displaced by ridges on a compatible card to move a blocking block (87) and allow a flap (89) to open.

Description

PAYMENT SYSTEM

The present invention relates to a system for making a payment from an account.

Conventional payment systems include payment cards, such as credit cards or debit cards, which contain information including, amongst other things, an account number identifying an account from which a payment is to be taken whenever the card is used. Transactions can be made in a variety of ways e.g. over a counter in a shop, over the internet, over the telephone, by text on a mobile phone etc. A problem with many conventional payment systems, in particular credit cards, is that if someone obtains details of the account number, amongst other things, this can be used to take payments from the account. The account holder can inform the account provider that unauthorised use has occurred in order to stop further unauthorised use. However, before the account holder realises that payments are being taken from their account, a number of unauthorised transactions may already have taken place.

According to a first aspect of the present invention there is provided a system for making a payment from an account of a user, the account being associated with a plurality of personal account numbers capable of authorising payment therefrom, the system comprising: a payment device from which one of the personal account numbers is readable; authorisation means arranged to recognise the personal account number and authorise payment; and updating means arranged to change the readable personal account number.

According to a second aspect of the present invention there is provided a payment device for selectively accessing funds to make a payment from an account of a user, a plurality of personal account numbers being associated with the account and capable of authorising payment from the account, the payment device having one of the personal account number readable therefrom and comprising updating means arranged to change the readable personal account number.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings in which: Figure 1 is a schematic diagram of a system for making a payment from an account according to a first embodiment of the invention; Figures 2 and 3 show front views of a payment card which is part of the system of Figure 1; Figure 4 shows a rear view of the payment card of the first embodiment in a first condition; Figure 5 shows a rear view of the payment card of the first embodiment in a second condition in which an identification part of the card is being separated from a display part of the card; Figure 6 shows the identification part of the card of Figure 5; Figures 7a to 7c show a disposable memory card for use with the payment card of the first embodiment; Figure 8 shows a further front view of the payment card of the first embodiment; Figures 9a to 9 show an end view, a top view and a bottom view respectively of the payment card of the first embodiment; Figures lOa to lOc show sequential steps in a process wherein the card of the first embodiment is inserted and removed from a payment machine; Figure lOd shows a prior art card being attempted to be inserted in the machine; Figure 11 shows a view of the card of Figure 10 partially inserted in the payment machine; Figure 12a shows a rear view of a payment card according to a second embodiment of the invention; Figure 12b shows the identification part of the part of the card of Figure 12a; Figures 12c to 12e show a disposable memory card for use with the payment card of the second embodiment; Figure 13 shows a key for interpreting a bank statement; Figures 14 to 16 show statements relating to low, medium and high payments respectively made using a payment card according to the present invention; Figures 17a to 17b show a statement relating to payments made from the account of figures 12 to 14; and Figure 18 shows a front view of a payment card according to a third embodiment.

Referring to Figure 1, there is provided a system 1000 for making a payment from a bank account of a user. The system comprises a payment device in the form of a payment card 2. The payment card 2 has a memory 40 which is able to be interrogated by a processor 42. The processor 42 is connected to input means 44 and a display 24. The card 2 also comprises a magnetic strip 74 which contains information relating to the identity of the user.

The bank account is provided at a bank, which includes a bank memory 1010 which is able to be interrogated by a bank processor 1020. As shown schematically in Figure 1, a display reader 1030 connected to the bank processor 1020 is able to communicate with the display to obtain information from it and a magnetic strip reader 1040 is able to communicate with the magnetic strip to obtain information from it.

Deposits can be made into the bank account in the normal way.

Associated with the bank account are a plurality of personal account numbers. If the user quotes one of the personal account numbers when making a transaction e.g. when purchasing goods or services over the internet, over the telephone, over the counter or in any other known way, then payment in relation to the goods or services is authorised by providing one of the associated personal account numbers during the transaction. Referring to Figure 1, the personal account number can also be read directly from a payment card 2 by a machine such as an ATM.

Referring to Figures 2 and 5, the system includes a payment card 2. The payment card 2 comprises an identification part 4 and a display part 6.

The display part 6 forms the main part of the card and the identification

I

part 4 is a removable part of the card 2. The payment card 2 is substantially of the same form and dimensions as a standard payment card such as a debit or credit card.

The display part 6 which forms the main part of the card 2 and has a front side 8, an opposite rear side 10, a top edge 12, a bottom edge 14, a leading end edge 16 and a trailing end edge 18. On the front side 8 of the display part 6 is printed the user's name 20. Also on the front side 8 there is provided input means in the form of a keypad 22. Adjacent the keypad 22 there is provided a display in the form of a rectangular electronic display panel 24. Running parallel to a longitudinal axis of the rectangular display panel 24 and parallel to the top 12 and bottom 14 edges of the display part 6, there are provided two elongate ridges 26, one on either side of the display panel 24. Adjacent to a lower one of the ridges 26, near the bottom edge 14 of the display part 6, a first low authorisation button 28, a second medium authorisation button 30 and a third high authorisation button 32 are provided. These buttons also allow a user to input information - their function is described in detail below.

Referring to Figure 4, the rear side 10 of the display part 6 includes an identification number 34 for identifying the payment card 2. Adjacent the leading end edge 16 the display part 6 comprises a SIM (subscriber identity module) card slot for receiving a SIM card 36. Adjacent the leading end edge 16, the display part 6 comprises a battery slot for receiving a battery 38.

Referring to Figure 1 the memory 40 is capable of storing 3600 personal account numbers. The processor 42 is able to interface with a disposable memory card 46 (Figures 7a to 7c) when this is placed in a memory card slot (not shown) provided on the display part 6. The processor 42 detects the presence of the memory card 46 in the memory card slot and arranges for personal account numbers stored on the memory card 46 to be downloaded onto the memory 40 for later use.

The personal account numbers are only downloaded once the processor has verified that the memory card 46 belongs to the same user as the display part 6. This is achieved by the processor 42 reading identification information from the memory card 46 when it is in the memory card slot and verifying it against information accessible to the processor 42 via interrogation of the memory 40.

In other embodiments when the processor 42 detects the presence of the memory card 46 in the slot, a user is prompted to enter a PIN number to authorise downloading of the personal account numbers.

Referring to Figures 3 to 5, on the top edge 12 towards the trailing end edge 18, the display part 6 includes an on/off button 48. On the bottom edge 14 towards the trailing edge 18, the display part 6 includes a screw receiving aperture 50. The screw receiving aperture 50 is arranged to receive an Allen screw 52 which has a head 54 arranged to be rotatably driven by an Allen key 56. The head 54 has an Allen key receiving aperture. The Allen key 56 is generally L-shaped having a driving portion with a hexagonal head and a handle portion at 900 to it. On the bottom edge 14 near the leading end edge 16 of the display part 6 there is provided an Allen key receiving aperture 58 for receiving one of the legs of the L-shaped Allen key. When the leg of the Allen key is inserted in the Allen key receiving aperture to its fullest extent, the other leg of the Allen key rests substantially flush with the leading end edge 16 of the display part 6.

On its rear side 10 the display part 6 has a rectangular identification part receiving slot 60. One of the sides of the rectangular slot 60 is provided adjacent the bottom edge 14 of the display part 6. The rectangular receiving slot 60 is arranged to receive, and therefore has the same dimensions as, the identification part 4.

The identification part 4 forms a removable panel on the rear of the main part of the card and is generally rectangular having a front surface 62, a rear surface 64, an upper edge 66, a lower edge 68, a leading end edge 70 and a trailing end edge 72. The identification part 4 includes information identifying the user and the payment card 2 as is available with known credit or debit cards. This is information such as the user's signature, a card verification number, a sort code number, and dates from when the card is valid and when the card expires. As well as being displayed, this information is also stored in a magnetic strip 74 provided on the rear surface 64 of the identification part 4. On the lower edge 68, towards the trailing end edge 72, the identification part 4 has an attachment flap 76 extending forwardly and substantially perpendicularly from the front surface 62 of the identification part 4. The attachment flap 76 has a screw receiving aperture 78 formed therein - this screw receiving aperture 78 is arranged to receive the previously mentioned screw 52.

When the identification part 4 is located in place in the rectangular receiving slot 60 provided on the display part 6, the screw receiving apertures 50, 78 of the display part 6 and the identification part 4 are aligned and the screw 52 is receivable in both apertures to fix the identification part 4 to the display part 6.

Referring to Figures 7a to 7c, the disposable memory card 46 is generally rectangular having a notched corner. The memory card 46 is made generally of a plastics material having a fold line 80 formed through it substantially centrally. On one side of the memory card 46, an information carrying element 82 is inset into the plastics material. The information carrying element 82 can hold up to 3000 personal account numbers. As previously mentioned, the memory card 46 is locatable within a memory card slot on the display part 6 of the payment card 2.

The personal account numbers stored on the information carrying element 82 are able to be downloaded onto the memory 40 via instructions from the processor 42 of the payment card 2. Once the personal account numbers have been downloaded, the memory card 46 can be folded along its fold line 80 which also runs through the information carrying element 82 as shown in Figure 7a in order to render the information inaccessible.

The memory card 46 can then be disposed of.

In use, the user switches on the payment card using the on/off button 48.

A software application stored on the memory 40 provides a start-up prompt on the electronic display panel 24 prompting the user to enter a code in the form of a PIN number (see Figure 2) in order to be able to continue use of the payment card 2. The user enters the PIN number via the keypad 22.

If the correct PIN is not entered the payment card 2 is not able to provide a personal account number for authorising payment from the bank account. Once the correct PIN is entered, a personal account number capable of authorising a payment from the bank account is displayed on the display panel 24 (see Figure 3). The personal account number which is initially displayed on the display panel 24 is a low authorisation personal account number. A low authorisation personal account number is capable of authorising a payment from the bank account of up to a predetermined limit - in this case 100. Similarly, a medium authorisation number is capable of authorising a payment from the bank account of a higher predetermined limit - in this case 500. Similarly, a high authorisation personal account number is capable of authorising a payment from the bank account of up to an even higher predetermined limit - in this case 10,000.

The first personal account number that is displayed on the display panel 24 is a low authorisation number so that if the card is used by an unauthorised user, the unauthorised user will only have access to a low authorisation personal account number, thus minimising the amount they can spend.

If the user wishes to select a medium or high authorisation personal account number, this is done by pressing the medium authorisation button 30 or the high authorisation button 32. When it is desired to choose another personal account number, the user is once again prompted for input of a PIN. If the user has a change of mind and wishes to select a low authorisation personal account number, the low authorisation button 28 can be pressed. The personal account number is displayed on the display panel in a manner which is visible to the user so that it can be read off and used in an internet/telephone payment and also in a manner which can be read by a payment machine when using the payment card 2 to withdraw cash or to pay for goods over the counter.

Locking of the payment card 2 via a PIN system is optional for the user.

The user, using the keypad 22, can choose to have the PIN locking system deactivated so that upon start-up no PIN is required to be entered in order to use the payment card 2 - this may be desirable for some users who may find it difficult to remember a PIN. However, it will be appreciated that deactivating the PIN locking system is less secure for the user.

When the payment card 2 is new, the memory 40 includes a database of 1000 low authorisation personal account numbers, 1000 medium authorisation personal account numbers and 1000 high personal account numbers. When a payment is made using the payment card 2, the selected personal account number is used up and cannot be used again - the bank processor 1020 recognises that the personal number has been used and does not allow it to be used again. When there is only a predetermined number of any one of the low, medium or high authorisation personal account numbers left unused, this is recognised by the bank processor 1020. In this case, when there are only 200 low authorisation personal account numbers or 200 medium authorisation personal account numbers or 200 higher authorisation personal account numbers left, the processor recognises this.

Referring to Figure 1, when there are only 200 low authorisation personal account numbers left, the bank recognises this by detecting the use of a predetermined low authorisation personal account number - this is possible since the low authorisation personal account numbers are used in a predetermined order. Therefore there is no need for the bank to count the personal account numbers of any type (low, medium or high) which have been used but merely detect the presence of a particular personal account number to indicate that a predetermined number have been used.

In an alternative embodiment, the bank counts the number of low, medium or high authorisation personal account numbers which have been used.

Stored on the memory 40 is a counter software application which is run by the processor 42 to count the number of low, medium and high authorisation personal account numbers which have been used and therefore determine the number which are stored in the memory and are still unused.

When there are only 200 authorisation personal account numbers left unused, the bank generates 1000 more low authorisation personal account numbers suitable for authorising payment from the bank account up to a limit of 100 per payment. At the same time if the bank also knows the number of medium or high authorisation personal account numbers which have been used, it may also generate more of these types of personal account number at the same time to top-up the number of medium and high authorisation personal account numbers to 1000 again.

Once the new personal account numbers have been generated, they are loaded onto the information carrying element 82 on the memory card 46.

The bank then sends this memory card 46 to the user. The user then inserts the memory card 46 in the memory card slot of the display part 6 of the payment card 2. As previously indicated, the processor 42 detects the presence of the memory card 46 in the memory card slot and downloads the personal account numbers stored on the information carrying element 82 onto the memory 40 after verification that the card 46 is intended for use with the display part 6. An indication that this transfer is complete is provided by a message on the electronic display panel 24. Once the transfer is complete, the user removes the memory card 46 from the memory card slot and folds it along its fold line 80 (see Figure 6c). Since the fold line 80 runs through the information carrying element 82, when the memory card 46 has been folded along the fold line 80, information on the information carrying element 82 is no longer accessible since the information carrying element 82 is damaged. The memory card 46 can then be thrown away in the knowledge that the personal account numbers are not accessible by anyone else.

As an additional known security measure, when the payment card 2 is due to expire, the bank will send Out a new identification part 4. This removes the necessity to send out a whole new payment card 2, which includes more electronic components and is therefore more expensive to produce than the identification part 4. When the user receives the new identification part 4, it is simple to replace the previous identification part 4. Firstly, the user detaches the old identification part 4 from the display part 6 by removing the Allen key 56 from the Allen key receiving aperture 58 and using the Allen key 56 by inserting it into the aperture provided in the screw head 54. In this way the screw 52 can be rotated by the user to remove it from the payment card 2. When the screw 52 has been removed, the identification part 4 will no longer be attached to the display part 6 and it can be manually detached from it. When the new identification part 4 is positioned in place in the rectangular identification part receiving slot 60, the Allen key 56 is used to rotate the screw 52 to securely attach the identification part 4 and the display part 6 together.

Once this has been done the Allen key 56 can be reintroduced into the Allen key receiving aperture 58 and it remains there until it is needed again.

Referring to Figure 8, if the user wishes to check the number of personal account numbers left unused, a request is made by inputting a predetermined prompt via the keypad 22 in the form of a prompt number.

The number of used low authorisation, medium authorisation and high authorisation account numbers is displayed on the electronic display panel 24. At the same time, the time and date of the last use of each type of personal account number is also displayed - this allows a user to more easily check whether any unauthorised use of the card has occurred. In other embodiments, the number of lower authorisation, medium authorisation or high authorisation personal account numbers which remain unused can be additionally or alternatively displayed.

Referring to Figure 9, the payment card 2 also includes a connector socket 84 provided on the leading end edge 16 of the display part 6. The connector socket 84 is profiled to receive a connector pin 86 of a bank payment machine 88 to allow electrical communication between the payment card 2 and the machine 88.

Referring to Figures lOa to lOc and Figure 11, two levers 85a, 85b are provided laterally aligned with the elongate ridges 26 on the display part 6 of the payment card 2 such that when a user correctly places the card 2 into the payment machine 88, the levers 85a, 85b are displaced upwardly.

The payment machine also comprises a moveable restricting block 87 and an entry flap 89. The block 87 is arranged to be movable between a first blocking position in which movement of the entry flap 89 is prevented such that a card can not be placed in the machine 88 and a second access position in which movement of the entry flap 89 is allowed such that the card can be placed in the machine 88. Figures lOa and lOd show the block 87 in the blocking position and Figure lOc shows the block in the access position.

As the card 2 is inserted into the machine 88, movement of the levers 85a, 85b upwardly caused by engagement with the elongate ridges 26 of the card 2 causes movement of the block 87 from the blocking position to the access position. The levers 85a, 85b displace the block 87 by physical engagement with it. This allows movement of the flap 89 and insertion of the card 2.

In contrast, if a conventional card, not having such elongate ridges is attempted to be inserted in the machine 88, the levers 85a, 85b are not displaced and so the block 87 remains in its blocking position.

Consequently, the flap 89 abuts against the block 87 and does not open when a card 2 is pushed against it and entry of the card is thus prevented (see Figure lOd).

Once the card 2 is in the machine the elongate ridges 26 on the display part 6 of the payment card 2 are guided in elongate channels 27 of the payment machine 88. The payment card 2 is thus is guided into position through engagement between the ridges 26 and the channels.

Via the communication between the payment card 2 and the machine 88, the bank processor 1020 reads the display 27 to obtain the personal account number displayed on it and it 1020 also reads the magnetic strip 74 to obtain identity information from it. The processor 1020 compares the personal account number which is displayed on the display 27 to a list of personal account numbers stored in its memory 1010. If the displayed personal account number matches an unused valid personal account number, payment can be authorised. If the personal account number matches a used personal account number or is not recognised as a personal account number capable of authorising payment, then the payment is not authorised. When the payment is authorised the bank processor 1020 then controls dispensing of cash as requested by the user.

The processor 1020 updates the balance of funds in the account following the transaction. Details of each transaction and the updated balance are stored in the bank memory 1010.

At regular intervals, e.g. monthly or after a predetermined number of transactions, the bank processor 1020 interrogates the bank memory 1010 and produces a statement showing transactions which have been made to/from the account.

Referring to Figure 14, extracts from a statement of the user's account are shown. The statement details include the type of transaction (i.e. low authorisation up to a limit of 100 per transaction), a transaction date, further details on the transaction (i.e. card transaction, cash withdraw, account credit etc.), a transaction location, a transaction reference number 90 and a transaction amount.

The transaction reference number 90 includes information on the number of transactions which have taken place, the payment card brand, the personal account number and whether or not the transaction has been made using a low, medium or high authorisation personal account number. In this way, the user is able to check various security details and more easily identify whether or not unauthorised use of the card 2 has taken place. In order to be able to interpret details provided on the statement more easily, symbols and a key 1300 (shown in Figure 13) are provided on the statement. One or more stars are used to represent the number of transactions which have taken place. The first three digits are allocated to identification of the transaction number. If only one star is displayed adjacent the transaction number 90, then only the first digit is indicative of the number of transactions which have taken place - the remaining two allocated digits are zeros. Similarly, if two stars are displayed next to the transaction reference number 90, the first two digits are indicative of the number of transactions which have taken place - the remaining digit is a zero. Similarly if three stars are displayed next to the transaction reference number 90, all three digits are indicative of the number of transactions which have taken place. Therefore the first ten transactions are represented by one star, the next ninety transactions are represented by two stars and the next nine hundred transactions are represented by three stars.

The next two digits are indicative of the brand of the card being used. It may be possible to access funds from the account using more than one brand of card. In the present embodiment this is not the case and so the statement shows the card's brand is represented by the same two digits (00) for all of the transactions. If a different card was used to access funds from this account, a different set of digits would appear in these two columns. The brand of the card is represented by a triangular symbol which appears in the key.

The next nine digits make up the personal account number. It will be seen that this is different for each transaction. Therefore, as previously indicated, if an unauthorised user somehow discovers one of the personal account numbers, it will not be able to be used again if it has already been used because the bank processor 1020 recognises that the number has already been used and will not authorise the transaction. If the number has not been used, it will only be able to be used once. Digits of the personal account number are represented by a circle.

The final two digits of the transaction reference number 90 have a rectangular symbol next to them which indicates that these digits represent the type of transaction (low, medium or high authorisation). In this statement, all transactions relate to a low authorisation payment i.e. payments up to and including 100 - therefore these two digits are 11 for all transactions.

Referring to Figure 15, extracts from a statement for the user's medium authorisatjon transactions are shown. This statement is made up in the same way as the statement shown in Figure 14 except that it relates to medium authorisation transactions having a limit up to and including 500 per payment. It will be noted that the last two digits are all 85 in this case since they all relate to medium authorisation transactions.

Referring to Figure 16, extracts are shown from a user's statement of high authorisation transactions for payments in value up to and including 10,000 per payment. This statement is made in the same way as the statements shown in Figures 14 and 15 except for the upper limit provided for each transaction - the final two digits in this case are 07.

On all of the statements shown in Figures 14 to 16, it will be noted that payments made into the bank account appear on all of the statementsrelating to each type of transaction. This is because funds paid into the account are accessible via low, medium or high authorisation. Referring to Figures 16a to 16c, extracts from a complete statement are shown.

The complete statement is a consolidated version of the statements shown in Figures 13 to 15 and includes each transaction reference number 90 along with a separate indication of whether each particular transaction reference number 90 relates to a low, medium or high authorisation payment. On the complete statement, an account balance after each transaction is also provided so that the user can more easily judge whether or not a payment will need to be made into the bank account e.g. if funds are becoming low.

Referring to Figures 12a to 12e, a payment card 100 according to a second embodiment of the present invention is identical to the payment card 2 of the first embodiment except that it includes a chip 92 instead of the magnetic strip 74 of the payment card 2 of the first embodiment. The chip performs the same function as the magnetic strip 74. The card 100 is used with a memory card 46 identical to that shown in Figures 7a to 7c for use with the payment card of the first embodiment.

Referring to Figure 18, a payment card 300 according to a third embodiment of the invention is identical to the card of the first embodiment except it does not include elongate ridges 26. The transaction reference number 390 is in the same format as described previously i.e. the first two digits represent the transaction number, the next two digits represent the card brand, the next nine digits represent the personal account number and the final two digits represent the type of account.

Various modifications may be made to the present invention without departing from its scope. For example, different numbers of personal account numbers may be stored in the memory or on the memory card.

In particular, different numbers of personal account numbers may be used in relation to each type of account (low, medium or high authorisation).

A new memory card may be sent out by the bank or other account provider when there are a different number of personal account numbers left unused for each different type of transaction (i.e. low, medium or high authorisation).

The personal account number may be arranged to be updated less frequently than every transaction - for example every two or three transactions - or randomly - or randomly within a range e.g. every 1 to 3 transactions. Alternatively, the personal account number may be arranged to change after a predetermined amount of money has been spent in transactions. The number of disposable memory cards which need to be produced/sent to a user may thereby be reduced.

The different types of transaction i.e. low, medium or high authorisation may be associated with different accounts i.e. the same card may be used with different accounts which are arranged to be debited depending upon the type of transaction. For example, there may be different accounts for each type of authorisation payment i.e. a low authorisation account, a medium authorisation account and a high authorisation account. The accounts may be held at different banks.

The code may be an alphanumeric code or any other suitable code, instead of a PIN number.

Claims

1. A system for making a payment from an account of a user, the account being associated with a plurality of personal account numbers capable of authorising payment therefrom, the system comprising: a payment device from which one of the personal account numbers is readable; authorisation means arranged to recognise the personal account number and authorise payment; and updating means arranged to change the readable personal account number.

2. A system according to Claim 1, wherein the updating means is arranged to change the personal account number in response to a request for an updated personal account number.

3. A system according to Claim 2, wherein the request is a request from the user.

4. A system according to Claim 2, wherein the request is an automatic request.

5. A system according to Claim 4, wherein the request is a request from an account provider.

6. A system according to Claim 5, wherein the updating means is arranged to change the personal account number in response to a predetermined number of payments.

7. A system according to Claim 6, wherein the updating means is arranged to change the personal account number in response to each payment.

8. A system according to Claim 5, wherein each payment has a value and the updating means is arranged to change the personal account number when the total value associated with the payments since the previous change of personal account number reaches a predetermined amount.

9. A system according to any preceding claim, wherein the readable personal account number is provided in machine readable form.

10. A system according to any preceding claim, wherein the readable personal account number is provided in user readable form.

11. A system according to any preceding claim further comprising storage means arranged to store the personal account numbers.

12. A system according to Claim 11, wherein the payment means comprises the storage means.

13. A system according to Claim 11 or Claim 12, wherein the storage means is arranged to store a predetermined number of personal account numbers.

14. A system according to Claim 13 further comprising a counter arranged to count the number of personal account numbers which have been used.

15. A system according to Claim 14, wherein when a predefined number of stored personal account numbers are left unused, generation means is arranged to generate further personal account numbers for storage in the storage means.

16. A system according to any preceding claim, wherein each personal account number is capable of authorising a payment from the account of up to a preset limit.

17. A system according to any preceding claim, wherein the payment device comprises a payment card.

18. A system according to Claim 17, wherein the card comprises an electronic display arranged to display the personal account number thereon.

19. A system according to Claim 18, wherein the card further comprises lock means arranged to lock the display such that the personal account number is not visible until the lock means is unlocked by a user.

20. A system according to Claim 19, wherein the lock means comprises a code activated lock means, the card comprising a keypad for input of the code by the user.

21. A system according to Claim 17, when dependent on any of Claims 11 to 17, or any of Claims 18 to 20, wherein the storage means comprises memory provided in the card.

22. A system according to any preceding claim, wherein the personal account numbers are arranged to be loaded onto the payment device from a memory card.

23. A system according to Claim 22, comprising means for checking the memory card is intended for use with the payment device prior to loading.

24. A system according to Claim 22 or Claim 23, wherein the personal account numbers are arranged to be loaded in response to entry of an alphanumeric code, such as a PIN, by the user.

25. A system according to any of Claims 22 to 24, wherein the memory card is arranged to be disposable once the personal account numbers have been loaded onto the payment device.

26. A system according to any of Claims 17 to 25, wherein the payment card comprises an identification part which contains information concerning the identity of the user and a display part which is arranged to display the personal account number.

27. A system according to Claim 26, wherein the memory card is removably mountable in the display part.

28. A system according to Claim 26 or Claim 27, wherein securing means is arranged to secure the identification part to the display part of the card.

29. A system according to any of Claims 16 to 28, wherein a plurality of sets of personal account numbers are provided, the personal account numbers of each set having different known preset limits and the payment means comprising selection means for selecting the set from which the readable personal account number is taken.

30. A system according to Claims 17 to 29, wherein the card is arranged to be locatable in a payment machine, the payment machine comprising restricting means to selectively restrict entry of a card therein.

31. A system according to any of Claims 17 to 30, wherein the restricting means is arranged to restrict entry such that only a card according to any of Claims 17 to 30 is allowed to enter the machine.

32. A system according to any of Claims 17 to 31, wherein the restricting means comprises a movable block arranged to be displaced by a projection provided on the card.

33. A system according to any of Claims 17 to 32, wherein guide means in the form of a ridge and groove arrangement is provided between the payment machine and the card.

34. Payment device for selectively accessing funds to make a payment from an account of a user, a plurality of personal account numbers being associated with the account and capable of authorising payment from the account, the payment device having one of the personal account number readable therefrom and comprising updating means arranged to change the readable personal account number.

35. Payment device according to Claim 34 for use in the system of any of Claims 1 to 33.

36. A system or card substantially as hereinbefore described with reference to any of the accompanying drawings.