Going to the UK next summer with the family, for a few weeks, and we want to bring our nanny, she is Thai and has a passport but has never travelled outside Thailand before; both my wife and i have UK/EU passports (as do the kids).She will travel with us and stay with us for the whole period and then return (with us) to Thailand.

Does anyone have any experience of obtaining a nanny visa and can flag up any potential issues? I had a look on the UK visa site and it looks fairly straightforward, though one issue, maybe, is that she does not have a formal contract of employment with us (though she has worked for us for 2 years) , is this a big issue? should we get one drawn up? is it worth using an agency for her visa? if so, do any of them specialize in this kind of visa service?any other issues to watch out for?

See 3. Documents you must provide under Domestic Workers in a Private Household visa.

You must also provide information about your job, including:

• a letter from your employer confirming that when you enter the UK you’ll have worked for them in the same job for at least 1 year
• a completed and signed statement of your terms and conditions of employment

You must also provide 1 of the following documents covering the same period of employment:

• pay slips or bank statements showing payment of salary
• confirmation of tax paid
• confirmation of health insurance paid
• contract of employment
• work visa, residence permit or equivalent passport endorsement for the country where you’re currently employed by your employer
• visas or equivalent passport endorsement if you’ve travelled with your employer before

So a formal contract of employment is optional; another document from the list can be used instead.

Whether to use an agent or not is up to you; but if you can provide all the evidence to show she meets the requirements, I don't see the need.

If you do consider using an agent, I recommend that your read Visa agents first.