My 19 year old niece has previously traveled to the UK twice with me, my wife and daughter when she was younger. She wants to go back this year with her friend who is 20 for a short trip but even though she's 19 as she's still under the Age of Majority in Thailand does she have to get permission from her parents etc to travel abroad?

Many thanks for any info.

did she have to get 'permission' when she travelled with you

Yes so I'm assuming she still has to. I just like it confirmed as she's older now.

May I ask did she have to obtain written permission from both parents?

20 is the 'magic' Age of Majority in Thailand

I guess she's still considered a child so must need permission. Thanks all.

Under Thai law, yes she is still a child as she is under the Thai age of majority.

So she should get the letter from her parents.

She may not be asked for it by Thai immigration; but better to have it and not need it than need it and not have it!

Which passport will she be using?