Yes, mortgage pre-approvals can affect your credit score if you obtain more than three pre-approvals. Because each approval requires the lender to pull your credit rating, it will look like you are suddenly applying for a lot of credit and subsequently reduce your score. However, credit rating agencies recognize that the pre-approval process means you may apply to more than one, so more than three appears to be the number that triggers a rat-ing issue. You can get around this by starting with a mortgage comparison tool and choos-ing the best three options it provides to request formal pre-approvals from.