1. Click on Banks
2. Click on Edit Account Details
3. Click on the Payments tab
4. Click on Accounts Payable Electronic Funds Transfer to highlight the row and then click the button at the bottom for Edit Payment Options
5. Click on EFT General
6. Click the drop down next to Company ID Prefix and choose User Defined and enter the correct number in the space
7. Click Ok
8. Save and Close the Bank