This is the difference between theory and practice.
In theory, you can get in for six months or ‘as long as the border guard allows’. We all know that all of us are honest human beings that would never put a toe out of the line, and therefore the border guard can be sure that you will leave the UK at the end of your allowed six months, even though the flight has not been booked yet.
If I turn on the irony in the statement above, we are in the middle of the practice. Of course you are technically allowed six months, but the immigration officer wants to know:
- Will you leave at the end of your trip?
- Do you have the funds to sustain yourself during your trip?
- Will you attempt to work illegally, abuse the NHS or do something else that goes against the laws or well-doing of the UK?
- And will you really leave at the end of your trip?
I have emphasised the leaving bit here, but the funding is at least as important. It is on you to show them that you can do it and that you won’t be relying on anything handwavy. Remember, you are not allowed to work and they really don’t like people coming in as a tourist and then working.
So if you walk up to the border control at your airport of entry, they’ll start a little chat and ask you when you intend to leave. And if you don’t have a good answer there, it’ll go South very quickly and you might just get the worst.
For an idea of what the worst could be, see this question: What are the visa rules for US speakers, at UK conferences, who may be getting paid?
The visitor rules are in Immigration Rules Appendix V
