Still wrestling with the marriage visa thing. So, after you get the visa can you renew it indefinitely? Or do you do your 90 day check ins and then after a year you need to reapply for the marriage visa?
TLDR : Answer Summary
In Thailand, while you cannot renew a marriage visa indefinitely, you can apply for annual extensions as long as you meet the necessary requirements. Each year's extension requires submitting new documents, similar to when you first applied. Additionally, you must perform 90-day check-ins throughout the year. After a year, instead of a simple renewal, a new application process based on updated documentation is required.