The National Audit Office, the British Parliament's oversight body, said on the 20th that the UK needs to rebuild its customs border with the European Union after leaving the European Union, but the related construction costs soared due to long-term delay and uncertainty.

According to the estimate of the British government, the implementation of customs border arrangements after "Brexit" will cost at least US $6 billion.

In 2016, the UK held a referendum to decide "Brexit". After years of negotiations, it finally officially "Brexit" on January 31, 2020, ending the transition period of "Brexit" at the end of the year. Since the UK will leave the EU's unified market and customs union on January 1, 2021, the customs border between the EU and the UK needs to be rebuilt.

According to Agence France Presse, the European Union immediately resumed customs inspection of goods imported from the United Kingdom, but the British government has postponed the resumption of customs inspection of EU goods for five times since then. Currently, only food, animal and plant products imported from the European Union are subject to incomplete inspection. The Director of the National Audit Office, Gareth Davis, said in a report released on the 20th: "It is more than three years since the end of the transition period, and it is still unclear when the comprehensive inspection will be in place."

According to Reuters, the British government only started to set new customs rules this year, and launched corresponding measures in stages. The first stage is the new "border target operation mode", which will be implemented from January 31; In the second phase, the port entity inspection facilities will be introduced and implemented from April 30; The third phase is planned to be implemented from October 31, setting requirements related to customs declaration.

The National Audit Office pointed out that enterprises engaged in trade between the UK and the EU face additional costs and administrative burdens. The National Audit Office criticized the "2025 Border Strategy" issued by the British government in 2020 for lacking a clear timetable and cross sectoral implementation plans.

The spokesman of the British government responded that the customs border arrangement "is making good progress". Phased measures have been launched in January and April this year. The government also intends to introduce simple measures to benefit traders.