Betting and Gaming Duties Act 1981

14 (1) Where an amount is due from any person on account of bingo duty but the Commissioners are unable to ascertain the amount of duty properly due from him—

(a) by reason of his failure to keep or to produce or furnish to the proper officer any books, records, accounts or other documents which he is required or directed under this Schedule to keep, produce or furnish, or

(b) by reason of his failure to take or permit to be taken any other step which he is so required to take or permit to be taken, or

(c) by reason of such books, records, or accounts being materially incomplete or inaccurate,

the Commissioners may estimate the amount of duty due.

(2) Without prejudice to the recovery of the full amount due or to the making of a further estimate, the amount estimated shall be recoverable as duty properly due unless in any action relating thereto the person liable proves the amount properly due and that amount is less than the amount estimated.