How can I obtain a long-term visa to stay in Thailand for a year as a tourist with an invitation letter?

If its available in your country the METV is the way to go. You can get upto 9 months stay.

It's simple

Just travel out of Thailand every 3 months and go back in a few days later

Do student hv online class 1 time a week that can travel too

You are asking the wrong question. You cannot do anything on a tourist visa except be a tourist. You are needing to get the correct visa for the purpose of your visit. Whoever has given you your letter should be helping, or at least pointing you in the right direction.

Alen, I think you should first ask advice from the person who issued the invitation letter. Ask if they can advise you of the procedure you should follow to accept the invitation. And then also ask the nearest Thai embassy. Good luck

Kad sam zadnji puta isao za tajland dosao sam sa turistickom vizom otisao u skolu i oni su pripremili sve dokumente i sa tim sam isao u imigraciju da mi promijene u ed vizu i ostao 6 mjeseci. Mozes birati 6 mjeseci ili godinu dana.

I wouldn't say a year is classed as living here and it is possible to do it on tourist visas

One of my mates is leaving Thailand next week after 15 months here on TV and visa exempt. A few border bounces a few extensions and maybe a week or 2 in Cambodia and it's possible just be prepared for a few headaches and always have plan b when you approach immigration at arrivals.

Sorry, we have enough yogis already. Application denied

Haiya.. what is your invitation letter? 😂

You will not be staying in thailand for one year with a tourist visa simple and having correct visa for your stay is still not a guarantee of entry but having correct visa for your stay will help Chokh di you are going to need it

an invitations letter isn't changing anything, not when you apply for a 6-month multi entry Tourist Visa nor when you apply for a 60-days single entry Tourist Visa. There is no 1-year tourist visa. You can get two 60-days TR-visa in a row, including the 30 days extensions on each, within one calendar year and will probably be denied a third one, because "living in Thailand for one year" is not what the Thai Immigration expect real tourists to do. You could, however, get a 15-months stay out of a Non-Imm-ED Visa if you start courses in a reputed language school or university inside Thailand. You will but need to attend classes, as online-schooling is not possible under the ED-visa scheme, and Immigration will random check your presence

Who is the invitation letter from? Is this to do with a job, or study?

You cannot live in Thailand with tourist visas. There's no such thing as a tourist visa that will let you stay in ChiangMai, or any country in the world, for 1 year.

You will need to get the proper visa for your stay. And "because I want to" is not one of the reasons to qualify for a long term visa.