The UK government has warned businesses that it won’t tolerate the repeated and criminal practice of incorrectly completing customs documents to avoid new charges.

The claims follow the second round of Border Target Operating Model (BTOM) rules that were introduced in April, including documentary and physical checks on medium- and high-risk plant and animal products.

In a letter to traders sent out last week, the Department for Environment, Food and Rural Affairs (Defra) wrote that many businesses and logistics firms are making “continuous and/or deliberate” errors that could lead to the avoidance of recently introduced charges.

Many medium-risk goods were falsely being marked as low-risk, while high-risk goods were being downgraded to medium-risk.

Defra also suggested that traders had been trying to include multiple Export Health Certificates (EHCs) – documents that must accompany medium- and high-risk goods – on a single Common Health Entry Document (CHED), when only one should be included. With the cost of each document reaching as much as £145, the department suspects this to be a money-saving measure.

The missive also noted that some traders were failing to include EHCs at all for imports of meat and dairy products, as well the corresponding certificate for plants.

Port Health Authorities have been told to take action if they encounter this kind of misrepresentation, which constitutes a criminal offence.

Two of the three phases of BTOM have now been implemented. The first phase, introduced on 31 January, required the submission of relevant documentation, such as EHCs and CHEDs. Since 30 April, there have been checks on this documentation, as well as physical inspections on some goods.

The final phase, which will be introduced 31 October, will require EU imports to be accompanied by a safety and security declaration.