Can you pay for a fast track through immigration in Thailand?

Pre-book or fly business class.

You need to prebook your fast track but we’ll worth it this time of year, I was I the  queueing for over three hours last year

If you,re 70 or over you can use fastrack

Depends on the airport, and depends on the day. It's not fast track which is a completely different section of the airport. But there is an express line for people with business classes and first class along the side, and sometimes you can pay cash to join that line.

If you want fast track then you need to prebook that from one of the services available online.

You have to pre book