If you will require a mortgage for the purchase of a property it is often advantageous to obtain an offer in principle before you start your hunt for a property. While the New build offer in principle that I mentioned above will guarantee a mortgage offer of a specific amount against a specific property, a general offer in principle is not associated with  a specific property rather it is a financial pre-approval of the borrower and it will tell them - subject to a property valuation  - how much they will be able to borrow, over what term and with what conditions.

Credit checks should not be needed for a pre-approval nor should any payment either to the back of a broker, the bank will take it on good faith that you have good credit history (of course it they will check during the actual mortgage application) and both bank and broker work in the hop that they will secure your business later down the line. 

The preapproval will enable you to budget accurately and make confident decisions. It will also put you in a stronger position when it comes to any negotiations when you find a property to buy.