There are a number of visa options for Thailand. Depending on how old you are or what you wish to do in Thailand the visa would differ. Below you will find a number of visa options which are the most common for foreigners in Thailand. There are also limitations to each visa and this has also been explained below.
This Thai marriage visa is if you have a Thai wife. You would have to have your marriage certificate as well as 400,000THB in a local bank account as well as photos of the two of your together and also a map to your house or apartment in Thailand. You will also need to have the birth certificates of your children who are Thai if you are not married and wish to obtain a visa as you are here to support your children. The process takes about 30 days to complete and then you have to report your address to Thai immigration every 90 days. Note that you are not allowed to work on this visa but can apply for a work permit with it. Note depending on your country you will now also need to have your finger prints letter from Thai Special Branch police.
This is the Thai retirement visa and you will need to be 50 years old or over the age of 50 when you apply for this visa. You will also need to show a bank balance of at least 800,000THB when you apply for this visa. You will also need a medical certificate from the local Thai hospital for this visa. The implementation of fingerprints will more likely than not follow as it has for the marriage visa in Thailand. Check with your immigration lawyer in Thailand about this as it takes 10 days to obtain the finger prints letter from the police.
Not a very common visa to be applied for as this is for those who wish to enter their children into a Thai school or university and are in Thailand to look after them. You will need to speak to an attorney about the process for this visa.
These are mainly for those who are going to work in Thailand. You will need to have all the needed documentation from the company or school for this visa at the Thai embassy. These are very difficult to obtain as they will check if you had one before and if you applied for a work permit with it. They are very strict in Asia about this specific visa. Once you enter Thailand with this visa you have 90 days to apply for a work permit.
Most countries may enter Thailand on a 15-day visa waiver (land border) or 30 days at an international airport. If you are planning on stay in Thailand for more than 30 days, then it is best to apply for this visa in your home country. Speak to an immigration lawyer about your visa options when coming to Thailand.