If the dealer overpaid tax due to an error on the return, the dealer may file a claim for refund. The claim must be filed within 3 years from the date the tax return was filed or 2 years from the time the tax was paid, whichever is later. The dealer's claim must be filed on form TTB F 5620.8. The claim must include detailed and sufficient evidence explaining why the dealer believes the tax was overpaid. The claim and supporting documentation must be mailed or delivered to the address shown on the form.