So here is a very specific question, and hoping someone may be able to advise.

I know a Maechi (Buddhist nun) who is about to travel to SriLanka on a pilgrimage.

Maechi is a Thai national, living in Thailand, but also has UK nationality, and has a UK Passport.

I read conflicting info about Thailand allowing 2 passports.

The Maechi last entered Thailand about 2yrs ago on a one way flight from the UK, using the Thai passport.

Her plan is to travel to SriLanka on the UK passport and has already booked plane tickets with UK passport details.

I guess the reason for using the UK passport was ease of visa for UK nationals.

My concern is, upon exiting Thailand on a UK passport, there is no valid departure card (UK passport never used when entering Thailand).

Upon returning to Thailand, using the UK passport, Maechi is given a 30-day tourist entry.

Maechi then continues life as a Thai citizen, does not leave after 30 days and potentially overstays for an enormous amount of time.

My thinking is she takes the hit on the airplane ticket already purchased, and buy another using the passport details on the thai passport.

Thoughts welcome from others with experience of 2 passports.

The lady should leave and re-enter Thailand using her Thai passport.

The UK passport should be used to enter and leave Sri Lanka.

A friend of mine is a dual US/Thai citizen. She leaves the US using her US passport and enters Thailand using her Thai passport. When she leaves Thailand, she is stamped out using her Thai passport & enters her destination using her US passport.

She shows both passports if there are any questions and has never had any problem.

No problem to change passports

When she checks in for her flights she will show both passports to overcome any visa questions the airline might have.

She will only show her Thai passport to immigration on departure from and entry to Thailand. At Sri Lanka she will only use her UK passport for entry and departure.

Hi everyone, thank-you for the information. I have passed this on.