The 599-page withdrawal agreement covers the following main areas: This title deals with the customs regimes of goods transferred from the United Kingdom`s customs territory to the EU customs territory and vice versa (Article 47). Processes that begin before the end of the transition period „are considered an intra-Union transfer with regard to import and export authorisation requirements under EU law.“ The agreement also deals with the cessation of temporary filing or customs procedures (Article 49). Negotiations for a free trade agreement began in March 2020. As a result, the UK would leave the EU on the effective date of a withdrawal agreement, which is expected to be concluded no later than two years after notification of the withdrawal request, i.e. 30 March 2019, unless the European Council, in agreement with the United Kingdom, unanimously decided to extend the deadline (which required the agreement of all Member States). The extension was granted on 26 March 2019 at the request of British Prime Minister Theresa May. An extension has been granted in the UK until 22 May 2019, provided that the UK House of Commons approves the withdrawal agreement negotiated during this period. If the House of Commons did not accept the withdrawal agreement, the deadline would not be extended until April 12, 2019. In this case, a decision on a further extension of the deadline would also be foreseen if the United Kingdom declared, before 11 April, that it would hold elections to the European Parliament (EP). However, regardless of the outcome of the negotiations on free trade agreements, customs formalities should be followed at a later date which, until now, do not apply to trade with the UK as an EU member state. On the issue of the Irish border, there is a protocol on Northern Ireland (the „backstop“) which is attached to the agreement and establishes a position of withdrawal which will only come into force in the absence of effective alternative provisions before the expiry of the transition period.
In this case, the UK will eclipse the EU`s common external tariff and Northern Ireland will stick to aspects of the internal market until such an event is carried out. Neither party can unilaterally withdraw from this customs union. The aim of this backstop agreement is to avoid a „hard“ border in Ireland, where customs controls are needed.  As of 1 January 2021, the Uk will no longer be part of the internal market or customs union. Even if an agreement on future relations is reached by the end of the year, the EU`s relationship with the UK will change radically and will be very different from those of the UNITED Kingdom, which was a member of the single market.