If you hurry up and try to quickly reach an agreement in principle and fill out the application incorrectly, it can be rejected – which hurts your credit score. But it is of the utmost importance that contractors receive their AIP from a consultant who understands contracting! Having a mortgage in principle is not mandatory, but there are several good reasons to make one. You may be wondering why, in principle, you are interested in a mortgage in the first place instead of just applying for an actual mortgage. The simple answer is that obtaining a mortgage is in principle faster and less expensive. They can often be sorted in less than an hour if there are no problems, and it should only take a few days at most. This exempts you from seriously going in search of a home and allows you to make a firm offer for a home that you like the look of. .