You still need to provide your own copies of that information, which can be verified against other sources. If you can't provide that information, then you're l

You still need to provide your own copies of that information, which can be verified against other sources. If you can't provide that information, then you're likely to not do well during the audit. So, you do want to make sure you've got your own copies of those files, whether hard copy or scanned. But for 99.99% of US citizens, a single file cabinet is likely to be more than enough.