How long before my visa expires should I apply for an extension in Thailand?

In Thailand, you should start the visa extension process when you have 30 days or less left on your current visa. After applying for the extension with the required documentation from your employer, you will typically receive a 30-day under consideration stamp, followed by a one-year extension later on. This process also applies to your wife and child, as long as you provide the necessary documentation for their extensions.