We have a female employee who entered Thailand several years ago on an Multiple Entry O Visa based on marriage to a Thai. Shortly thereafter, she was employed and got a Work Permit. Present extensions based on Work Permit. She now wishes to change to Extension based on marriage. Can this be done at local Immigration or does she have to depart Thailand and apply for visa? We are getting conflicting info on this.

As long as still on extension of stay she should be able to change at next renewal. If between will take local office agreement and not sure where they would stand.