Hi Giorgio,
It can be tricky to know exactly what you can claim when you have business and personal elements on the same trip. HMRC is strict when it comes to claiming expenses that have a dual purpose (work and personal use).
Some things that can help work out if you can claim:
Was your trip extended for the purpose of working - eg, if you weren’t working, would your trip still have been the same length or would it have ended sooner?
Were you required to be at your client’s site to carry out the work?
If you were required to be working there, and that portion of your trip was dedicated solely to work, then you should be able to claim reasonable expenses, such as a meal and part of your accommodation costs. Please be sure that you have all your receipts/proof of purchase for anything you claim, so it’s documented.
Thanks,
Katie