Some 27 London boroughs said they had no problem with properties being let for short periods and this did not require any planning permission.
But Southwark, Tower Hamlets, Islington, Kensington and Chelsea, Westminster and Camden warned people who let properties for short periods without planning permission could be served with enforcement notices.
With rumours of a two grand a week price tag on one bedroom flats near to Games venues, if you do decide to go ahead, Direct Gov has 'rent a room' tax advice to keep you on the right side of HMRC.
If you've got spare rooms going begging, check out online community Airbnb which already has Olympic listings available. If the only spare room you've got is in your back yard, you can even pimp that out on Camp In My Garden.