Buying a property to rent out is done using a mortgage that is dependant on the rental income the property is capable of generating. Normally a minimum deposit of 15% is needed and the monthly rent will need to be around 125% of the monthly mortgage interest payment, calculated at the lenders base rate. The lender will want to see you have a minimum level of personal income so that you could meet the mortgage payments at times when your property may not be generating any rental income. You can have numerous buy to let mortgages and special schemes are available to portfolio borrowers.