Create validation rule in Expenses to prevent submission of expense unless BIC code entered

Summary:

Hi Oracle community,

The business has requested to make the BIC code field mandatory in the Bank Account Details entered by employees in the Expenses module for specific countries, which has been completed. This works for new employees who cannot create a bank account in Expenses without entering a BIC code.

However, existing employees can continue to submit expenses even if there was is no BIC code and this causes failure of payment runs when Expenses are being paid.

Is it possible to create some sort of validation rule in Oracle to prevent Users from even submitting an Expense if the BIC code is missing (and ideally throw out an error that says something like "ensure all mandatory fields are completed in the bank account"?)