Testimonal document in the context of scholarship to study abroad?

Question

I'm translating subtitles for a movie and I ran into this sentence:

1. Teacher: You have some missing documents. You need a signed testimonial from your parents.
2. Student: But I'm already 18. Technically, I don't need a signature from parents.

This one is a thai movie and I'm not even sure subtitles are fully correct. By the way I read around the web that in the context of job interviews /applications the testimonial letter is something looking like a recommendation letter but not as formal. I was wondering what could this be in the context of scholarships or travels (it's not specified whether the document is needed for one or the other).

Thanks in advance for your help!

Answer 1

This document could have several names. In terms of official travel between countries, an unaccompanied minor might need a letter of consent from their parents in order to get through customs, for instance (WikiHow).

In this case, since the teacher is asking about the form and the situation sounds less formal, you might compare a testimonial to a permission slip or form. Here is Wikipedia's explanation:

A permission slip is a form that a school or other organization sends home with a student to a parent in which the parent provides authorization for minor children to travel under the auspices of the school or organization for an event, such as a field trip.

In effect, the document establishes that the parents approve of their child traveling.