Pembrokeshire County Council is urging local exporters to prepare for the full effect of Brexit.
The advice comes after HM Revenue and Customs (HMRC) announced that it is extending the deadline for businesses to apply for customs support funding.
The scheme - first announced in September, 2019 - had been due to close at the end of last month.
To date, applications have been made for around £18.5 million out of a possible £26 million, meaning there is at least £7.5 million left to claim from HMRC.
As well as supporting recruitment and improved IT capability, the money applied for so far could potentially fund nearly 15,000 training courses to help traders submit customs declarations.
During the transition period following the UK’s departure from the EU – from 1st February to 31st December 2020 – there will be no change to the way businesses trade with the EU.
Businesses that complete customs declarations now have until 31st January, 2021 - or earlier if funding is fully allocated - to apply for grant funding to help them increase their capacity to do so.
Jesse Norman, Financial Secretary to the Treasury, said: “The UK will be leaving the single market and customs union at the end of 2020, and businesses will need to prepare to submit customs declarations.
“Customs agents, freight forwarders and fast parcel operators can take advantage of the extended period by applying for grants to help them scale up and get ready.
“Customs processes can be handled by a business directly, but most businesses currently trading outside Europe use a customs agent.”