Hi everyone 
I am going to London next week. It is my first time since Brexit and I wanted to know how your experience with entering the UK has been since? If there were some difficulties for instance. I got a letter example from TH for entering the UK and got a bit scared how serious it could get.
Thanks!
Don’t use that letter!
There are some other threads about this. At airports, entry is often by e-gates, without a person asking you any questions. But if asked, you are just a tourist. Not a pet sitter.
Ok, that is from Australia, but that makes no difference.
At US borders, the THS letter has gotten sitters in problems.
That is enormously helpful, thank you!
But it is still weird that TH sends this letter although it might get HS into trouble…
At least, border issues can be discussed now on this forum. Until a year ago or so, that was a taboo subject.
Moderation of this forum has become much better since then.
Don’t ever use that THS letter!!! Unless you want to be on the next plane out! You are a tourist on holidays, visiting friends!
Say that you are a tourist. You might even want to book an AirBnB for the first night, in case they want to see evidence. I think I would do that if I was entering from Germany. I have a German passport and it NEVER works at UK e-gates. No idea why. When I was flying home from other countries, I sometimes went through the UK to change planes there, and as the e-gate didn’t work, I always ended up talking to an official who asked me what my plans in the UK were. Thankfully I just had to say that I was flying on to Ireland and they were happy.
I live in Ireland, so that makes it much easier for me to visit the UK, as there is no passport control for passengers arriving in the UK from Ireland.
What is the reason that the TH Letter might cause trouble?
Really?!? 
Most border officials will still see pet sitting as work and the letter will alert them even more than you are planning to “do work” in the UK.
Petsitting is work, or at least can be work. There are people making money that way. And even without money, you are still being compensated by the HO in the form of accommodation. So don’t mention petsitting. Also not when they ask where you will stay. Say whatever is plausible (hostel, B&b, friends), but do not mention petsitting.
The THS letter adds an extra layer of problems. It shows that you knew what you were doing. And it suggests that there is an agency/company sending you. And it kind of talks down to the border official.
As an EU passport holder, I have been in and out of the UK many, many times since Brexit. You don’t need to worry at all! It is all e-gates, and you won’t even see or speak to a person. Just get in the queue for EU passport holders, slide your passport through the e-gates, and ta-da, you’re in the UK!
The arrival process really has not changed since Brexit. I guess EU citizens are just expected to know that they are not allowed to work in the UK anymore, and cannot stay longer than 6 months at a time. The UK government can track how long you’ve been in the country anyway (from when your passport was last scanned), and it is impossible for EU citizens without settled status to be (legally) hired anywhere in the UK. So, they don’t place any further security checks at the airport - nobody will ask you questions, you just go through e-gates as per usual. 
ONCE (and only once, when Brexit was still fairly fresh) I was asked (not in the UK, but from the country I was leaving from), how long I was staying in the UK, and why I was going there. I said “visiting a friend for a few weeks” and they waved me through. Never asked for any further proof, no addresses, no phone numbers, nothing. They honestly don’t care as long as you’re not overstaying and not being paid for anything. You certainly won’t get questioned in the UK.
I put my hosts’ address and contact info in my phone and remember what they do for a living, because friends know stuff like that if asked. And I say that I’m a tourist if asked.
I’m American and usually the e-gates work for me. They weren’t in service during my last visit to the UK in November, one of several post-Brexit, so I was glad that I’d prepped for a human agent doing screening. Oddly, the agent asked whether I had family in the country, which I don’t.
America is one of the worst places to arrive in imho.
Hi Cookie
What is the THS letter?
You can find those letters (four now) on this page:
It is not good advice. It has gotten some sitter members in trouble. And of course HOs too, when their confirmed sitter was not admitted to the country.
Hi Karen65, read this link from THS website, NEVER print & carry these letters EVER!
An experienced sitter with over 100 sits told us they book refundable accommodation on Booking.com for the place where they are sitting in case immigration need evidence of their holiday. Once they clear the border they cancel the accommodation booking. We do this now too in foreign counties. We even go as far as deleting any reference to THS or sitting from our phones when travelling internationally.
I delete other stuff related to THS as well, because I saw a video series of border officers in various countries that included checking phones for evidence of travelers’ plans and communications when they became suspicious.
I store stuff in the cloud. I travel solo, so if I can’t retrieve info, my husband can. He doesn’t like to travel anywhere as much and stays home with our dog.
When I sit abroad, I arrive early and spend days at hotels, so I can sightsee without responsibilities.
How is it legal for them to search ur phone?
Each country has its own laws and regulations for how they screen travelers, including visitors. You can decline, but they can refuse you entry, of course.
When it comes to entering countries, if they suspect you of something, they will interrogate, search, etc., as they please. That includes your person and clothing, baggage, electronics, etc. They even X-ray some people suspected of carrying drug packets internally.
In the video series, they would sometimes call the people the traveler was supposedly visiting, ask them Qs and see whether their accounts lined up.
If the border agents aren’t satisfied, they can detain you, arrest you (if they find anything criminal) or send you back on the next flight. This is true around the world.