Berkshire Olympic Accommodation Filling Up
Two thirds of hotels and B&Bs we've called in Berkshire say they are already noticing an increase in bookings for the Olympics.
Thousands of people are expected to watch the rowing, Paralympic rowing and sprint canoeing at Eton Dorney.
Accommodation at some hotels nearby has already been fully booked by rowing teams.
If you fancy cashing in, Heart has been told people could make thousands of pounds by renting out their house or spare room.
But Bob Gaiger from HM Revenue and Customs says you must tell them first;
"The problem is if you don't tells us and there is a tax liability then obviously you would need to pay that tax and I suppose, potentially, there could be a penalty if you haven't told us."
Mr Gaiger says there are few other things to look out for;
"Your home insurance - are you covered if you are renting out your room? Make sure that you meet any health and safety requirements and if you have a mortgage, does your mortgage allow you to rent out a room?"
There's more information on what you need to do at www.hmrc.gov.uk/bst or you can call them on 0845 6032691.
Have you checked out the Rent-a-Room scheme? You can receive up to £4,250 a year tax free through this option. For more information click here.