Accommodating the data needed to process checks for payment under the Check Clearing for the 21st Century Act by using expanded fields of a financial data file. The financial data file can comprise the complete, original MICR data from an original or substitute paper check. The financial data file can comprise truncated data in conventional fields F1-F7 and untruncated data in expanded fields F10-F11. The financial data file further can comprise a result from an image quality analysis performed on an electronic image of the check. The untruncated MICR data and the electronic check image can be used to correct errors in the financial data file and to present the check for payment via a substitute check or an electronic image cash letter. The truncated MICR data can be used to electronically process the check via conventional means.