Universal Flat File (UFF) is the generic payment file format generated by the pay cycle of Accounts Payable (AP). UFF files are used by offices which have developed a banking interface with their local banks. Similar to system check payments, the local office needs to download the UFF payment file for further processing and interface to the local bank. If an office does not have a local interface, then a letter of instruction must be manually prepared and authorized to request the bank to execute a transfer for payment.