Different years may need different supporting information. You can call first, then discuss which records would help with the proposed review of unpaid taxes.
Keep different dates in different fields
A letter received this year may discuss a prior tax period. A saved file date can reflect when you downloaded a copy rather than when the underlying event occurred. Give these dates separate fields and use the document’s stated period for the year grouping. Where the period cannot be established, mark it as unassigned with a note. This preserves the evidence while preventing a convenient label from becoming an unsupported claim about which year the account question belongs to.
Use a stable way to find the original
Choose reference names that remain understandable across folders and digital copies. Record enough description to distinguish a return from a confirmation or notice without putting unnecessary sensitive information into the index. When you change a label, preserve the reason where it affects an earlier reference. Review the entries for duplicate documents and unclear versions. A stable index helps prepare a discussion about tax relief because you can point to the original source rather than relying on a year label whose meaning changed during sorting.