27 CFR §22.123

1. (a)Recording of losses. A permittee shall determine and record, in the records prescribed by subpart M of this part, the quantity of tax-free or recovered alcohol lost on premises—
   1. (1)At the end of each semi-annual period when the inventory required by § 22.162 is taken, or
   2. (2)Immediately upon the discovery of any loss due to casualty, theft or other unusual causes.
2. (b)Claims. A claim for allowances of losses of tax-free alcohol shall be filed as prescribed in § 22.125, in the following circumstances—
   1. (1)if the quantity lost during any semi-annual inventory period exceeds 1 percent of the quantity to be accounted for during that period, and is more than 10 proof gallons, or
   2. (2)if the loss was due to theft or unlawful use or removal, the permittee shall file a claim for allowances of losses regardless of the quantity involved.