How much deposit do I need for a buy to let?

Usually at least 25% of the purchase price, which is a good deal more than a residential mortgage asks for.

Some lenders will look at 20%, and a few at 15%, but the rates get noticeably worse as the deposit shrinks. The best pricing tends to sit at 40% and below in loan to value terms.

The deposit is not the whole cost of getting in. Stamp duty on an additional property, legal fees, a survey and any work the place needs all come out of the same pot, and stamp duty in particular catches people out.