26 CFR §44.6419-2 — -2 Credit or refund on wagers laid off by taxpayer.

1. (a)Laid-off wagers; in general. If a taxpayer accepts a wager and lays off all or a part thereof with another person who is liable for tax under section 4401 with respect to such laid-off wager, a credit may be allowed to such taxpayer in the amount of the tax due with respect to the amount of the wager so laid off, provided there is attached to the return for the month during which the wager was accepted and laid off by him the certificate prescribed in paragraph (d) of this section.
2. (b)Claim for refund. If a taxpayer has paid the tax with respect to a wager laid off by him, he may file a claim for refund of such tax on Form 843 or take a credit for the tax paid by him against the tax shown to be due on any subsequent monthly return. If a refund is claimed, Form 843 shall be completed in accordance with the instructions thereon and, in addition, there shall be attached to such form a statement setting forth the reason for claiming the refund, the month in which such tax was paid, the date of payment, and whether any previous claim for refund covering the amount involved or any part thereof has been filed. There shall also be attached to the Form 843 the certificate prescribed below. In the case of a credit, the statement and certificate shall be attached to the monthly return on which the credit is claimed.
3. (c)Credit or refund not allowed. No credit or refund will be allowed under this section if the wager is laid off with a person or organization not liable for tax under section 4401 with respect to such laid-off wager. No interest shall be allowed on any amount of tax credited or refunded under this section.
4. (d)Certificate required. The certificate prescribed for use in support of a credit or refund with respect to a laid-off wager shall be in the following form: