Technically the UK has left the European Union, but from the traveller’s point of view, nothing significant has changed during the transition phase. This comes to an end at 11pm GMT (midnight Western European Time) on 31 December 2020.

After that, life for British visitors to the EU becomes very different. The one exception is for Ireland, where very little changes: notably customs and motor insurance rules.

For everywhere else in Europe, these are the most critical changes.

Even if you have a burgundy passport with “European Union” on the cover, it will continue to be valid as a UK travel document. The problem is, from 1 January 2021, European rules on passport validity become much tougher.Read more

On the day of travel to the EU (as well as non-members Andorra, Iceland, Liechtenstein, Norway, San Marino, Switzerland and the plucky Vatican City) your passport must pass two tests.

1. Was it issued less than nine years, six months ago?

2. Does it have six months’ validity remaining.

The reason: the UK has traditionally given renewals up to nine months’ extra validity in addition to the normal 10 years. So a passport issued on 30 June 2011 could show an expiry date of 30 March 2022.

While this was fine when the UK was part of the European Union, British travellers must now meet the strict rules on passport validity for visitors from “third countries”.

In particularly, passports issued by non-member countries are regarded as expired once they have been valid for 10 years.

While the expiry date printed in the passport remains valid for the UK and other non-EU countries around the world, within the European Union the issue date is critical.

A passport issued on 30 June 2011 is regarded by the EU as expiring on 30 June 2021. Therefore if the holder attempted to board a plane to the European Union on New Year’s Day 2021, it would be considered to have insufficient validity and the airline would be obliged to turn them away – even though the British passport has almost 15 months to run.

Until September 2018, the government appeared unaware of the problem. Once the issue was identified, the practice of giving up to nine months’ grace ended abruptly.

EU fast-track lanes for passport control will no longer be open to British travellers, although countries that receive a large number of visitors from the UK, such as Spain and Portugal, may make special arrangements.

The process is likely to be slower, and with no guarantee of entry.

At present, all a border official can do is to check that the travel document is valid, and that it belongs to you.

From 1 January 2021, the official is required by EU law to conduct deeper checks. They may ask for the purpose of the visit, where you plan to travel and stay, how long you intend to remain in the EU and how you propose to fund your stay.

From 1 January 2021, the “90/180 rule” takes effect. For holidaymakers and business travellers who normally stay a long time in Europe, it has significant effects. You may stay only 90 days (about three months) in any 180 (six months).

Example: if you spend January, February and March in the EU – totalling 90 days – you must leave the zone before 1 April and cannot return until 30 June.

You will then be able to spend the summer in Europe until 27 September, when you must leave again – and can’t come back until Boxing Day.

Any time spent in the EU up to the end of 2020 does not count. So if you spend December in Spain, the clock does not start ticking until New Year’s Day.

The UK government says: “Different rules will apply to Bulgaria, Croatia, Cyprus and Romania. If you visit these countries, visits to other EU countries will not count towards the 90-day total.”

British citizens can stay as long as they like in the Republic of Ireland.

People who have a work or residential visa for a specific EU country will be treated differently.

Initially they will not be needed, but from 2022 (or possibly later) British visitors will need to register online and pay in advance for an “Etias“ permit under the European Travel Information and Authorisation System.

Previously there were no limits on the value of goods you could bring in from European Union nations. From the start of 2021, the European Union will be treated the same as the rest of the world – which means that there are now strict limits on what you can bring back free of duty.

For alcohol, the limits are 4 litres of spirits or 9 litres of sparkling wine, 18 litres of still wine and 16 litres of beer, which hopefully will see you through at least an evening. Arrivals to the UK will also qualify to bring in 200 duty-free cigarettes.

“Anything that increases the availability of tobacco is a negative step for public health,” the British Medical Association says.

If you exceed any of these limits, you will pay tax on the whole lot.

There is a limit of €430 – roughly £400 – for all other goods, from Camembert to clothing.

For more than 40 years, British travellers have benefited from free or very low-cost medical treatment in the EU and its predecessor organisations. The European Health Insurance Card (Ehic) and the document it replaced, the E111, have proved extremely valuable for many elderly travellers, and/or people with pre-existing medical conditions.

Since the EU referendum, the government has repeatedly said that it hopes to establish a reciprocal health treaty mirroring the European Health Insurance Card (Ehic).

For example, the then-health minister, Stephen Hammond, said: “The department recognises that people with some pre-existing conditions rely on the Ehic to be able to travel.”

The pretence has now been dropped, and the government now says: “You should always get appropriate travel insurance with healthcare cover before you go abroad.

“It’s particularly important you get travel insurance with the right cover if you have a pre-existing medical condition.”

The Association of British Insurers warns: “Claims costs within Europe are currently reduced due to the presence of the Ehic, which covers some or all state-provided medical costs.

“In the absence of the Ehic or similar reciprocal health agreement, insurers will inevitably see an increase in claims costs – this could have a direct impact on the prices charged to consumers.”

One bit of latitude: if you enter an EU country by 31 December 2020, your Ehic will remain valid until you leave that country.

Your licence carries the EU symbol but, as with passports, will still be valid as a UK document from 2021 until its expiry date.

The government says: “You may need extra documents from 1 January 2021. You might need an international driving permit (IDP) to drive in some countries.”

In fact, you may need two. A 1949 IDP (valid one year) is required for Spain, Cyprus and Malta, while the 1968 version (valid three years) is valid everywhere else in the EU.

The IDP is an antiquated document available at larger post offices. Take your driving licence plus a passport photo and £5.50 for each permit that you need.

Under the European Union 2009 motor insurance directive, any vehicle legally insured in one EU country can be driven between other European nations on the same policy.

From 1 January you will need a “Green Card” – an official, multilingual translation of your car insurance that demonstrate you meet the minimum cover requirements for the country you’re visiting.

Insurers will generally provide them free of charge, but require around two weeks’ notice.

At present, there is no legal agreement for any flights between the UK and the European Union from 1 January 2021.

The transport secretary, Grant Shapps, says: “The government’s priority is to ensure that flights can continue to operate safely, securely and punctually between the UK/EU at the end of transition period, regardless of the outcome of negotiations.

“Air travel is vital for both the UK and the EU in connecting people and facilitating trade and tourism, and we are confident measures will be in place to allow for continued air connectivity beyond the end of 2020.”

Some UK airport disruption caused by tough new passport rules may occur in the first few days if significant numbers of British travellers are denied boarding.

Ships will continue to sail and trains will continue to run, but the National Audit Office (NAO) warns that motorists taking their cars to France on ferries from Dover or Eurotunnel from Folkestone face waits of up to two hours once the Brexit transition ends – and that queues could be “much longer” in summer.

From 1 January 2021, the EU-wide ban on roaming charges for phone calls and internet use no longer applies to people with UK mobile phones. Providers will be free to impose whatever fees they wish.

But all the big providers have told The Independent they do not intend to bring back roaming charges.

O2 says: “We’re committed to providing our customers with great connectivity and value when they travel outside the UK. We currently have no plans to change our roaming services across Europe, maintaining our ‘Roam Like At Home’ arrangements.”

3 says: “We’ll give you free EU roaming just the same.”

EE says: “Our customers enjoy inclusive roaming in Europe and beyond, and we don’t have any plans to change this based on the Brexit outcome. So our customers going on holiday and travelling in the EU will continue to enjoy inclusive roaming.”

Vodafone says: “We have no plans to reintroduce roaming charges after Brexit.”

Should these or other providers introduce roaming charges, the government says it will cap the maximum for mobile data usage while abroad at £49 per month unless the user positively agrees to pay more.

For many years British travellers have been able to take a cat, a dog or even a ferret abroad with minimal formalities.

The government says it is “working with the European Commission to ensure a similar arrangement for pet travel between Great Britain and the EU from 1 January 2021.

“However, if an agreement is not reached there could be new requirements in place for those travelling with a pet from Great Britain to the EU from 1 January 2021.”

The hope is that the UK will become a “Part 1 listed country” under the Pet Travel Scheme. This would be the least bad option compared with what we have now.

But the issue is still not settled, so for now we have to assume the worst – that the UK will be “unlisted”. In that case, your pet must have a blood sample taken at least 30 days after its primary rabies vaccination. That sample will be sent to an EU-approved blood testing laboratory.

Then, you must “wait three months from the date the successful blood sample was taken before you can travel,” according to the government.

So if you start the process on 1 January 2021, you should be able to take a pet abroad from 1 May 2021.

One thing we do know: coming home will be no different. “There will be no change to the current health preparations for pets entering Great Britain from the EU from 1 January 2021,” says the government.