It is nearly impossible to keep up with changes to the rules for international travel during the pandemic.

Here the PA news agency answers 12 key questions about the current situation:

– What system is being used?

A risk-based traffic light system determines the testing and quarantine requirements for arrivals into the UK.

– What happens if I arrive from a green list country?

That is the low-risk tier, so all travellers are exempt from quarantine.

– What about testing?

You have to buy one post-arrival PCR test, which typically costs around £65.

– Sounds ok. What destinations are on that list?

The green list includes countries and territories such as Austria, Barbados, Croatia, Germany, Gibraltar and Malta.

– What about hotspots such as Spain, Italy and Greece?

They are all on the amber list.

– What are the amber rules?

Fully vaccinated travellers are treated the same as those arriving from a green country.

– How about those who have not had both doses of a coronavirus vaccine?

They must self-isolate for 10 days, and take two post-arrival PCR tests.

– Is there a way of reducing the quarantine period?

You can buy a third test to be taken on or after day five.

If you get a negative result, you can leave self-isolation.

– What about the red list?

This is the one to avoid if possible.

Arrivals from red list countries must stay in a quarantine hotel for 10 days.

– How much does that cost?

The price for solo travellers rose from £1,750 to £2,285 earlier this month.

– Ouch. What places are in the red tier?

There are currently 60 locations on the red list, such as Mexico, Pakistan, Turkey, and much of South America and Africa.

– Is there anything else I need to do?

Whatever country you arrive from, you must take a test in the three days before you travel and have filled out a passenger locator form.