If my US passport expires in November of this year (2020), and I want to travel in the UK beginning in March, will I need to renew to be able to board a plane back? I may be returning as late as May or June, so my passport would expire within 6 months when returning to the US.
You have an absolute right to enter the country of your citizenship. That's what citizenship means. They can punish you for lack of paperwork, but the punishment is civil, and can't include refusal to enter. However, they can detain you indefinitely while the proof of citizenship is obtained.
However, you cannot get on an airplane without proper documentation that meets the airline's and government's standard. So the "absolute right" is limited in practicality.
The passport needs to be merely "not expired" to fly home.
If you're doing a land crossing, an expired passport will work, but you should expect 5 lashes with a wet noodle.
If a citizen is doing a land crossing, a plain Real-ID, non-"enhanced" driver's license will also work, but expect 50 lashes with a wet noodle (comprising, in actuality, of some imposed delay and a stern lecture).
I believe they have some actual civil penalties they can throw at you if you make a habit of it (they know).
The UK does not have any minimum passport validity requirement other than that your passport is valid for the duration of your visit:
You must also:
- have a valid passport for the duration of your stay
You do not need to renew your passport for your proposed trip. Note that EU countries in the border free Schengen area do require 6 months validity for entry, but not for the whole proposed trip. Even if you want to visit France, for example, you don’t need to renew unless you enter less than 6 months before November.
You can return to the US as long as your passport is valid on the day of arrival. If your passport expires two months after you arrive, so much the better.
The US has a six month rule for the passports of certain foreign countries, but it does not apply to US passports. You should also check whether the countries you're visiting have similar rules. Many do, but the UK does not.