For those travelling within Britain Covid-19 restrictions are effectively over.
Rules for visitors from overseas were last updated on 30 August. See gov.uk/guidance/red-amber-and-green-list-rules-for-entering-england There are links from that site to the sites for Wales, Scotland and N.Ireland, where there are mostly minor differences in the rules as compared with those for England.
Those visiting England from other countries are still subject to restrictions, which vary according to whether which countries they have been in during the 10 days before arrival in England.
If you have only been in one or more green list countries you have to do the following
1. Take a Covid-19 test during the 3 days before you arrive in England. Obviously the result must be negative.
2. Book and pay for a Covid-19 PCR test to be taken on or before your Day 2 in Britain (arrival day is Day 0).
3. Complete and print off an online passenger locator form, detailing the addresses where you will be staying during your first 10 days in Britain, also the reference number of your Day 2 test booking.
There is no requirement to quarantine for those coming from green list countries, unless your Day 2 test is positive.
If you have been in an amber list country, in addition to the requirements for green list arrivals, you have to quarantine for 10 days after arrival in England at a specified address, UNLESS you have evidence that you have been fully vaccinated with an approved vaccine at least 14 full days (so 15 days) before arrival in England. For explanation of approved vaccines, see gov.uk/guidance/how-to-quarantine-when-you-arrive-in-england
If you have been in a red list country during the previous 10 days you have to pay to quarantine for up to 10 days from your arrival in England at a hotel on an officially approved list. This will cost more than GBP 2000 for two people travelling together. You will in effect be under house arrest during those first 10 days and will not be permitted to leave the hotel except to take further tests.
If you are coming from a red list country, you can of course avoid the 10-day incarceration by spending at least 10 days in an amber or green list country before arrival in England.
The rules for Wales, Scotland and N.Ireland are similar.
The take-home effect of these rules on those visiting Britain for a walking tour holiday is that this is only practicable
(a) if you have only been in green list countries during the previous 10 days;
or (b) if you have been in an amber list country (but not red list) and have proof of full vaccination with an approved vaccine at least 14 days before arrival in Britain.
We all hope for better times next year!