You may be eligible to apply for Thailand Permanent Residency that allows people to live in Thailand permanently without applying for an extension of temporary stay. In addition to the permanent residency book, an alien registration book will be issued, equivalent to the ID card held by Thai nationals.
The minimum requirement to apply for a Permanent Residency is to have at least 3 years of consecutive extensions issued from Thai Immigration. You must have 3 un-broken yearly extensions to qualify, which is just one of the many requirements when applying under the work/marry category. There are many other requirements and classifications for this application.
All Permanent Residency holders can have his/her name included on a house registration document. For example, if you buy a house in your wife’s name, you can have your name on house registration.
Obtaining a work permit is easier for a Permanent Resident than for a Non-Resident, but you still need to have a work permit if working.
No more Visa Applications.
No more 90-day checks.
No more Certificate of Residency.
Obtain a work permit without issues.
If the marital status were to change, it would have a major effect on your visa.
Buy a condominium without being required to transfer money from abroad.
Apply for naturalization under the law concerned.
Have Thai nationality granted to children who are born in Thailand/
Become a director of a public company. And,
Apply for an extension of stay or permanent residence for non-Thai family members.
The Residency Permit never expires unless revoked. To leave the country and return at will, though, you need to apply each year for a re-entry permit (endorsement) for 1,000 baht. Virtually this is the only contact you will make with the Immigration Department other than leaving through airports. However, you cannot be out of the Kingdom for any more than a year (important to know).
If you don’t leave Thailand, you don’t need to have any endorsement done. Also, you must present yourself at your local police station covering the area where you are resident once a year to stamp your book (Red Book). An outsider with permanent residency status will be eligible to apply for Thai citizenship after a certain period of time.