Will a 3-month return ticket cause issues if I enter Thailand without a visa?

when you exit thailand and enter new country and after that you enter again thailand you will get new visa entry

No you'll be fine

Just flown in yesterday with a one way ticket from Heathrow, no questions asked

Pre-Book your ticket for within the 30days of arrival to one of the other countries you plan to visit.

If you stay in Thailand for 3 months you get 60day evisa and exstend 30days at imigration. If you plan on leaving make sure you book exit flights to show on entry and dont over stay 30days at a time. Common mistake is not all months are 30 days.

Just a heads up.

It's looking increasingly likely the Thai Immigration are going to extend the visa exemption to 90 days.

Don't know when or for how long it will last.

Do not listen to all the stories from people saying, “I’ve never had a problem…”. I’ve never had one either. However, I’ve also been in this group for years and have seen the frantic posts from people denied boarding or entry. Fifty people may sail through with no problems. Do you want to be the fifty-first? Be prepared. You asked for a reason.

I think your be ok , I came here with a return flight for next June back in August , I have the retirement visa now , but no one said or asked any questions at all , that’s not to say they won’t of course but I wouldn’t worry too much .

I flew with Turkish in case you’re wondering, safe travels

You will not have any problem with your return flight ticket. I have a 5 months return ticket and I have a 60 days tourist visa. It will be your choice that you will applied a visa extension after 60 days or you will leave Thailand and you will come back.

You can be refused boarding it does happen and I have been asked myself over The last few years

One way ticket with no onward evidence and no suitable visa

If asked by immigration upon entry you are supposed to be able to show your onward ticket within 30 days if entering visa exempt. ( 60 days if on a tourist visa) you should also carry with you 20,000 Thai baht in cash to show you can support yourself and proof of your accommodation whilst in Thailand. I’ve entered Thailand by air 10 times in the last 2 years ( never by land) I’ve entered 9 times visa exempt. (5 times so far this year) I’ve never been asked by any airline to show onward travel but accept it could happen. I’ve never been asked by immigration to show my money or proof of accommodation ( I’ve always had it with me) but I’ve been asked twice by immigration to show an onward travel ticket. Once in Bangkok and once in Phuket so it can happen. Just my experience over the last two years. If you have never been to Thailand before I think it highly unlikely immigration will ask you for anything.

Take a trip to another country before day 31, return and get another 30 days, etc.

Have a ticket booked out of Thailand for country #1 to show your airline and immigration if you are asked. Do the same for each segment of your trip.

You should have your ticket back to UK for the last segment.

Bangkok is a very good hub for visiting all the neighboring countries.

Ask your airline. They're the only ones who realistically may ask for proof that you're leaving Thailand within 30 days if you fly without a visa.

You can also just plan one of your trips outside the country and buy the ticket and use that as proof.

I have flown into Thailand 3 times with a one way ticket

You will need a on-ward flight to prove you are going to travel and not stay longer then one month. You can check out onward ticket.com should you wish to stay longer then one month

You're staying 3 months without a break? Then going to other countries?