I searched around on this forum and on the net for this question but couldn't find it.

I've booked a through ticket to BKK with Thai and then onto CM with Thai Smile. Thai Airways allows 30kg for the international leg but I'm unsure if this 30kg allowance will be honoured by Thai Airways' sister franchise - Thai Smile since there normal luggage allowance seems to be 20kg.

Has anyone come across this issue before and if so do they know the answer - will the allowance be 20kg or 30kg as I've transferred from Thai Airways?

Question is: what is the originating point and are both flights on the same ticket. if they are on the same ticket the MSC (most significant carrier) rule comes into play. lets say your ticket starts in London. Then the baggage allowance of Thai airways will be applied for the whole of the journey.

You can find the rules explained on one of my blog posts http://www.airline-blog.org/2014/11/03/more-than-one-airline-on-the-ticket-what-is-my-baggage-allowance/

The are also links to the IATA documents for further study if necessary.

DXB - BKK - CNX going out and the reverse for the return.

I've read your page (many thanks) and it appears that as the Thai flight is the first and/or crosses the border the Thai Airways higher 30kg will apply for the outward leg. Will this also be applicable for the return leg?

Just checked the Thai domestic flight and it says Thai International even though I guess I could be on a Thai Smile flight. In which case I would hope my 30kg allowance would apply to both flights.

But hey this is Thailand so who knows!