Have I got this right?

[billyhouston]

My ideal scenario is: fly to Thailand and return to the UK after six weeks, during which time in Thailand I will take a short trip to Cambodia by air.

You should have no problems if you have purchased your flight to Cambodia before you depart UK and it takes place less than 30 days after your arrival. While it is technically possible that without the Cambodia trip you could be denied boarding, experience suggests that it is highly unlikely. With the Cambodia trip it's straightforward and, after all, you are only looking to stay 42 nights or thereabouts. You would not need to visit immigration to obtain an extension, that you would get when you fly in from Cambodia, or even if you return overland.

[christianpfc]

There is no limit doing this by air, but if Visa Exempt land border entries are limited to two per year. However, if done by air several times, especially back to back, Immigration may question whether you are really a tourist and in most cases tell you next time to get Visa, but depending on the Officer, they could deny entry.

From my experience, only an issue if you stay more than half a year within a year in Thailand on tourist visas or visa exempt.

...I am under the impression that there could be problems if, during the 30-day stay, you go to the immigration office and ask for an extension of the visa and it shows that the return ticket is in fact valid for a date in excess of the 30-day on arrival visa. In that situation it looks as if I am confident of being granted an extension to the 30-day visa. I'm not even sure if airlines flying between the UK and Thailand will let you book a return to the UK that exceeds the 30-day visa date for departure from Bangkok.

From memory, I was never asked for proof of leaving or date of leaving when I applied for an extension.

I was denied boarding (Eva Air in Taipei) on a trip to Thailand without visa and flight out of Thailand about 55 days later. I had to buy a flight out of Thailand within 30 days, did it on the spot and got it quick enough to get on my original flight.

[2lz2p]

Many thanks for this most comprehensive reply.

The area I'm having difficulty with is this question of the return ticket to the UK from Bangkok. Although in thirty years of visiting Thailand I have never been asked to show proof of a return airline ticket, I am under the impression that there could be problems if, during the 30-day stay, you go to the immigration office and ask for an extension of the visa and it shows that the return ticket is in fact valid for a date in excess of the 30-day on arrival visa. In that situation it looks as if I am confident of being granted an extension to the 30-day visa. I'm not even sure if airlines flying between the UK and Thailand will let you book a return to the UK that exceeds the 30-day visa date for departure from Bangkok.

My ideal scenario is: fly to Thailand and return to the UK after six weeks, during which time in Thailand I will take a short trip to Cambodia by air.

As you mentioned, it is very rare for Thai Immigration at an air entry port to ask to see an onward ticket. Based on your scenario, you should have no difficulty with Thai Immigration - if, during your initial stay of 30 days, you go to an Immigration Office for a 30 day extension and they want to see your onward ticket, your departure will be within the next 30 days. So no problem there.

As mentioned, the likely problem, and this depends on your airline, will be in boarding in the UK for travel to Thailand, as they may require your onward ticket show departure within the 30 day permission to stay granted upon entry for Visa Exempt arrivals. As I understand it, there are websites that for a small fee, cab provide a "ticket" for that purpose (not a real booking).

[maump]

Has anyone used the onwardticket.com scheme to have a cheap "flight" onward?

[Armando]

As mentioned, the likely problem, and this depends on your airline, will be in boarding in the UK for travel to Thailand, as they may require your onward ticket show departure within the 30 day permission to stay granted upon entry for Visa Exempt arrivals.

Not only departures from the UK. I have been stopped at Hong Kong (twice) for not having an onward ticket and once in Sydney. In Sydney I was told that Singapore has the same ruling.

[thaiophilus]

I'm not even sure if airlines flying between the UK and Thailand will let you book a return to the UK that exceeds the 30-day visa date for departure from Bangkok.

My ideal scenario is: fly to Thailand and return to the UK after six weeks, during which time in Thailand I will take a short trip to Cambodia by air.

They will certainly let you book it. I have done exactly this (for various other destinations as well as Cambodia) on several occasions.

They may ask questions when you check in but it has only happened to me on one occasion. SInce I had already made a genuine booking for an onward flight to the other country there was no problem ( i don't think they even asked to see it ).

[christianpfc]

Has anyone used the onwardticket.com scheme to have a cheap "flight" onward?

Twice. In both cases, I wasn't asked for an onward ticket.