When will my retirement visa extension take effect if I apply 45 days before expiration in Chiang Mai?

You can apply for a retirement visa extension in Chiang Mai when you have 45 days or less remaining on your current visa, which means you can apply any time after April 17, 2025, if your current visa expires on June 1. The new extension will begin from the expiration date of your current visa, so you will not lose any time by applying early.