We are flying from Australia to Bangkok Thai airways. We then need to transfer to a domestic Thai flight to Phuket. Do you collect our baggage, and clear customs and get to the domestic terminal or do we not collect our baggage and clear customs and go direct to the domestic terminal.Is there a free shuttle service from the international to the domestic. We have 2 boys aged 9 and 12. Any help would be grateful.

If you are flying with Thai from Australia ( SYD/MEL/BNE or PER ) at check-in tell them 'Please book us all thr way thru to Phuket', they will tag your bags to 'HKT' ( watch that, don't let them put BKK on the tags, make sure it says HKT ).
They will give you boarding passes to BKK and another boarding pass each for Bangkok to Phuket.
On arrival at Bangkok follow the signs that say 'Transfer to Phuket, Chiang Mai, Hat Yai' ( might even say Krabi now too )', any doubts just show your Phuket boarding cards to Thai staff and they will direct you.

Note: you will receive arrival cards before landing Bangkok, fill these in but present them at Phuket.

On arrival Phuket follow signs for international arrivals and you get stamped there and collect your baggage.

If you have any quieries just call your local Thai Airways office and they will go thru it for you, it is real easy.

This is all based upon the system not having changed.

Fenima, that is based on you flying both sectors with 'Thai' themselves. If you are flying some other carrier BKK to Phuket there's a whole different answer.

We are arriving in Bangkok from Narita with JAL, then on to Phuket with Thai Airways. Presume we will have to collect our bags in Bangkok and take them over to the Thai counter for Phuket?

Thanks especially JamesA. So much clearer now.

On most big international carriers you can send your bags all the way through when going to an international airport like Phuket (or Chiang Mai, Had Yai).

This way you will not go through immigration in BKK and do not have to pick up your bags. You will go to a transit area, then they drive you straight to the plane going to Phuket.