Using check digits
When creating a card service, you can optionally choose to link it to a check digit routine. This enforces that the reference number for the payment matches the format you specify, and that it has a correct check digit.
To add a new check digit routine:
Go to the Check Digits interface. To do this, click PayBridge > Manage Services in the main navigation bar, and then click on the Check Digits tab.
Click Create Check Digit in the top-right corner.
The details interface will open. Provide the following details, then click Save. Your check digit will be created, and you will now see it in the list of check digit.
|Title||The name of the check digit to be saved. Only used to identify the check digit, and can contain any characters or spaces.||Yes|
|Allow alphas||Whether to allow alphabetic characters in reference numbers.||Yes|
|Case sensitive||Whether the reference number is case sensitive, i.e. should 'A' and 'a' be treated differently?||Yes|
|Mask||This is the format of the reference number. A asterisk (*) denotes the check digit character, and a hash (#) denotes any allowed character.||Yes|
|Substitutes||A comma-separated list of values to substitute, e.g. A:1,B:2 (where any 'A' characters are substituted for 1, and any 'B's for 2).||No|
|Weightings||A comma-separated list of values the same length as the reference number, where each character in the reference number is multiplied by the corresponding value in this list.||No|
|Modulus||A number by which to divide the addition of all digits. The remainder of the this is then taken forward in the calculation.||Yes|
|Subtract from||A number to subtract the result of the modulus operation from to give the expected check digit||Yes|
|Check digit remap||A comma-separated list of values to substitute, e.g. 95:5,96:6 (where a result of 95 becomes a check digit of 5, and a result of 96 becomes a check digit of 5).||No|
Testing a check digit
To test a check digit calculation, click the 'Test Check Digit' button at the bottom of the page. This will open a popover which asks for a test reference number.
Provide a reference number and click 'Test'. The popover will show whether the reference passes the check digit test or not, with step-by-step analysis of the calculations carried out.