301-11.531—What documentation must the employee submit to substantiate a claim?

You must determine what documentation you require to be submitted with the employee's claim. It can include:
(a) A certified statement as prescribed in § 302-11.10 of this title or copies of completed Federal, State and local tax return for the tax year in which the taxes were withheld and paid.
(b) Copies of W-2's and Form 1099's.
(c) Any documentation received from the IRS identifying any interest or penalty payment (tax years 1993 and 1994 only).
(d) Any other documentation necessary to substantiate the claim.