When you post time using the Payroll Post program, it will automatically deduct that time from your employees' banks if the PR Type you are posting to has a Bank Type code entered in its Bank Type field. This must be a valid Bank Type code.
As you setup your Bank Types, there is a field called Associated Bank. This is used when you're posting hours in Payroll Post to a Payroll Type that updates a bank that has an associated bank code in Bank Types Maintenance.
For example, if you are posting time that you want to be removed from an employee's Sick Bank and you also want that time automatically removed from their Personal Bank, then you would enter the Personal Bank Type code in the Associated Bank field when setting up the Sick Bank Type's definition.
You should never enter the same Bank Type code for the Associated Bank as the one you are setting up. This is called a "circular reference" and would result in an error when posting time in Payroll Post to update that bank.
If you do not wish to update multiple banks at once as in the example above, you should leave this field blank to avoid any unintentional results or errors when posting time to update your banks.