Section 51(4) in The Police Enhanced Penalties Ordinance, 2005
(4)When a dealer is in default or is deemed to be in default in making the payment under section 37, section 38, section 39 or section 40, he shall be liable to pay simple interest on such amount at the rate of two percent per month from the date of such default for so long as he continues to make default in the payment of said tax.
