I came across a similar situation with HMRC. When in the Tobacco industry we had to supple data to enable tax to be verified. HUGE sums! My responsibility was the weight of finished products leaving the factory. That was the duty collection point, not shops. In effect we collected the tax for HMRC and the factory was a duty free premises.
We used to have a Customs Officer based in each factory. That changed in stages to just occasional visits from their offices. The early on site Officers were very good. The later visitors were hard work. They didn’t have knowledge of the agreed system of sampling plans, statistics, numerical detail. Our system was one that HMRC were pushing other companies to adopt as it was considered the best. We used a combination of an older mainframe system with linked test equipment, industry standard sampling plans, excel to produce summary reports. All verifiable and easily audited. We even paid duty on dust extracted as it contained small amounts (trace) of tobacco in a couple of areas. Having to lead the newer officers through the background to the system was a pain. Explaining the statistical tools caused glazed over eyes despite keeping it basic.
