@Jan *****************

Not required for most 'home' licences.

There won't be any repercussions during the visit, but the next time they apply UKVI might notice that they stayed longer than they said they would and this might affect their decision about a future visa. If there's a 'good' reason that they stayed longer than they applied for, it may be ok.

Section N

@Dani ********

Good question. I think there's a phone number but it be premium rated.

You need to show you are resident in Thailand. Ask VFS if a hotel address is acceptable. I doubt it; they normally need a utility bill or bank statement showing your address in Thailand.

90 days starts from the day you arrived in Thailand.

@Wylie ******

Yes, it can pay to play safe.

@Wylie ******

The IDP is not a driving licence, it's just a translation of your home licence into different languages. Thailand accepts English, so if your home licence is in English, an IDP makes no difference. That said, the police, car rental companies etc in Thailand are not legal experts and while technically unnecessary if you have a valid home licence in English, it may make things smoother if you have an IDP. Either way, you will need to get a Thai licence after 6 months.

As others have said, get the appropriate visa before leaving. You cannot extend a 30-day visa exempt entry at the airport anyway. I used my UK driving licence to get my first Thai licence, no need for an IDP.

No. And there's no requirement to be married for a UK Visitor visa.