I'm lucky - all of my tax returns have been The Most Straightforward Type, AND have been done online since that came in as the new standard, so there's very little LEFT in that file. Just need to go through and check what's past its seven-year mark (which is when the tax office stops caring, here. Or at least stops wanting you to store your records). So it should be pretty straightforward, honestly.

But if you have anything even slightly more complicated, oh man I bet that's a nightmare. *hugs, tea and/or booze as appropriate?*