URSULA von der Leyen, the European Commission President, turned Juliet after the Brexit deal was finally done last week, telling her British friends: “Parting is such sweet sorrow.”

But as Big Ben is reinstated and will bong 11pm tomorrow, Britain’s decision to leave the European Union finally becomes a reality. The safety net of the 11-month transition period is no more; we’ll be on our own.

At the weekend, Michael Gove, the Cabinet Office Minister, spoke of Brexit providing some “bumpy moments,” dubbed the understatement of the year by the SNP. Earlier this month, the CBI warned of a “tidal wave” of border bureaucracy that will hit British businesses come January 1.

But what practical changes will actually happen?

While the EU trade deal means there will be no tariffs or quotas, some rules and regulations UK businesses previously automatically observed will go as Britain will no longer be in the single market or customs union.

This means that firms which import and export goods will have to make customs declarations just like they have always done with countries outwith the EU. There will be a requirement for special licences for certain products like some foods and live animals.

The exception is Northern Ireland, where to maintain a frictionless border with the Republic, the region will continue to observe many of the bloc’s rules. Yet this means there will be some checks, say on food products, going from mainland Britain to Northern Ireland to ensure they comply with EU standards.

One key change will be the ending of the free movement of people; Britain, in taking back control of its borders, will introduce its own points-based immigration system.

People wanting to move to the UK to work, study or live will have to apply and pay for a visa.

For those Britons living in an EU country, certain protections will continue under the Withdrawal Agreement but there might be a need to meet requirements in some member states like having a secure job and applying for a residency permit.

For individuals, people have been warned to:

*have at least six months left on passports, except for trips to Ireland, which is part of the Common Travel Area;

*take out comprehensive travel insurance, particularly if they have a pre-existing health condition, as the European Health Insurance Card, that has provided free state healthcare on the continent from some 27 million Britons, is being phased out and replaced with an as yet undetailed UK Government Global Health Insurance Card;

*check the roaming charges on mobile phones as the guarantee on free roaming ends although the four main UK operators have made clear they have no plans to reintroduce fees;

*if intending to drive, take a driving licence, log book and valid insurance documents and there will be a requirement to contact an insurer six weeks before travel to obtain a green card that will prove insurance cover and

*get an animal health certificate from a vet 10 days before travelling as the current EU pet passport scheme will no longer apply.

Among other changes, online shoppers who buy items from the EU valued at more than £390 will have to pay customs duties. Handling fees and VAT could also apply on some items. This means that parcels face being held up in post offices until those fees and duties have been paid.

At border controls, Britons will now have to use separate aisles from those citizens from the EU, EEA and Switzerland and they will be able to travel to their destination in Europe without a visa, although there is a 90-day limit. Duty-free products will still be available but there will now be limits.

One politically controversial change is that membership of the EU’s Erasmus student exchange scheme will end with the UK Government promising to introduce a “better” programme named after the wartime codebreaker Alan Turing, which will be global rather than just concentrating on Europe.

Mr Gove, explaining the withdrawal from Erasmus, claimed the cost was unfairly high, noting: “The hundreds of millions of pounds additionally it would have cost us are better spent on making sure that disadvantaged children from less privileged backgrounds, who were often those who didn’t benefit from schemes like Erasmus, get a better education.”