My wife has just had her second Family Visa to UK approved. However as I am already in the UK and we are not sure on our return dates I am trying to find out if I have to get her a confirmed return ticket or can I just get her a single for now ( as AirAsia has singles for only 300 GBP ) .

I have looked on the UK Border agency site but without success.

Any advice would be appreciated.

There is nothing in the immigration rules to say that visitors to the UK must be in possession of a return or onward ticket in order to be allowed entry.

However, an Immigration Officer may ask her to show she either has such a ticket or the means with which to purchase one before admitting her.

Her problem could come when checking in with the airline, as they may refuse to carry her if she does not have a return or onward ticket. Check with them before buying a single.

A return ticket can smooth the wheels. UK bought tickets tend to be pretty inflexible but many of those bought in Thailand are better at allowing changes in return flight dates. The rules may not require a return ticket but not all Border Agency staff seem to be aware of this.