Modulus checking

Validating account numbers

Modulus checking allows payment originators to  confirm whether the sorting code and account number given by customers are compatible.  Performing modulus checks promotes efficiency and improves cashflow by reducing the risk of receiving returned payments.

The Validating Account Number document describes how modulus checking can be performed, either manually or by computer programme.  Modulus checks can be applied to validate customers’ account details before submitting an electronic payment such as a Bacs Direct Debit or Bacs Direct Credit.

How to use Modulus Checking Files

The specification document provided below describes the two general modulus checking methods available  and gives specific details of which to use for each sorting code.  Inside the back cover of the specification you will find details of how the specification differs from the previous version.  It also describes the structure of the data files available for download below for easy upload into modulus checking software.

Register for email alerts

To ensure that you have the latest version of the specification and the data files, download the latest versions using the hyperlinks below and register to receive an email notification when a new version of the specification and data files are available.

To cancel the notifications, or amend the email address the notifications are sent to, email modcheck@vocalink.com.

Related downloads

Modulus weight table data (.txt 69Kb valid from 02/05/08)
Sorting code substitution data (.txt 1Kb valid from 13/06/05)
Validating account numbers (.pdf 416Kb valid from 02/05/08)
Request for change (.pdf 441kb)

Note: Users of the information are reminded that VocaLink shall accept no liability for any loss or damage that may be suffered as a result of the incorrect processing of transactions resulting from the use of the information contained in the above named files.