A bit off topic but.... I was told if you have visa based on marriage you have to leave every 90 days but after you obtain an extension you only have to do 90 day reports. I don't think that sounds correct so I thought I would pose the question here....
I made a point on a similar thread about needing to use the correct terminology when speaking about such things. I was told I was wrong. Please allow me to try to explain.
A VISA is what is obtained, most of the time, outside of Thailand to be used to enter the country. Depending on which type of visa you require dictates where the visa can be obtained from. As an example a multi entry O based on marriage can be obtained at many consulates local to Thailand. A multi entry tourist visa can only be obtained in your home country.
When you get to Thailand, if you have a single entry visa, your visa will be stamped "used" and the visa itself has expired. What is stamped into your passport is a "permission to stay". A tourist visa gives you 60 days and a Non Imm visa will give you 90.
It is this "permission to stay" that is extended. You do not extend a visa.
So....if you have a multi entry visa you will get a permission to stay of 90 days. After that 90 days if you do not wish to or don't have the means to extend, you leave the country and come back. There are no rules as to how long you need to exit for. A quick hop over any land border is acceptable. You will of course need to satisfy the visa conditions of the country you enter. As you are leaving the country on or before the 90 days there is no need to go to immigration to complete a "notification of alien staying longer than 90 days" form. Upon your return your 90 days will start again at 1.
If you entered on a Non imm visa and have subsequently been to an immigration office here in Thailand and have applied for and successfully obtained a "permission to stay" based on marriage/retirement/employment you need to report to immigration every 90 days. In addition, if you need to leave the country at anytime during your permission to stay period you will need to go to immigration and apply for a re entry permit. If you do not, upon your return to Thailand, you will get a 30 day "visa excempt" stamp in your passport and will need to start the Non Imm procedure all over again.
Hope this helps.