HM Revenue and Customs (HMRC) has written to more than 200,000 businesses in the UK offering advice on how to ensure they can remain compliant with tax rules when making delayed import declarations for goods coming into the country from the EU.

As part of the UK's phased plan for implementing new import controls post-Brexit, importers of a range of non-controlled goods are currently able to delay sending HMRC information about these items until after they arrive in the UK. This aims to help businesses adjust to the new realities of trading with the EU now that Great Britain is outside the single market.

However, HMRC has reminded firms of a few key steps they must follow if they opt to do this rather than making a full declaration at the point of import.

Firstly, they must ensure they keep an accurate record of what is being imported every time their goods arrive in Great Britain. As a legal requirement, this must include the date and time of the import, a written description of the goods and the associated commodity code.

They must also be aware of the deadline for sending the supplementary declaration, which must be completed no later than 175 days after import. 

It can take up to 60 days for traders to receive authorisation from HMRC to make supplementary declarations, which means businesses that were importing goods in January and February and opted to delay their declarations should act now to ensure they can complete this documentation in time.

Katherine Green and Sophie Dean, directors-general for borders and trade at HMRC, said: "We know how hard businesses are working to adapt to the new rules and we want to do everything we can to help and support them to get things right. By offering the option to delay import declarations, we are giving businesses more time to prepare in what has been a challenging time for many."

HMRC also recommends traders appoint a customs intermediary to help handle this new paperwork on their behalf. As well as setting up online advice, the UK government has created an SME Brexit Support Fund which offers grants of up to £2,000 to smaller firms to pay for training or professional advice on adjusting to new customs, rules of origin and VAT requirements.