Use Form 843 if your claim or request involves:
(a) a refund of one of the taxes (other than income taxes or an employer’s claim for FICA tax, RRTA tax, or income tax withholding) or a fee, shown on line 3,
(b) an abatement of FUTA tax or certain excise taxes, or
(c) a refund or abatement of interest, penalties, or additions to tax for one of the reasons shown on line 5a.
Do not use Form 843 if your claim or request involves:
(a) an overpayment of income taxes or an employer’s claim for FICA tax, RRTA tax, or income tax withholding (use the appropriate amended tax return),
(b) a refund of excise taxes based on the nontaxable use or sale of fuels, or
(c) an overpayment of excise taxes reported on Form(s) 11-C, 720, 730, or 2290.