In general, it’s a good idea to apply to multiple mortgage lenders, but there are a few possible drawbacks. If you apply to multiple lenders outside of a 45-day period, the subsequent credit checks might not be treated as one. That can result in multiple dings to your credit score.Each application will require extra time, preparing and mailing or uploading multiple documents. And if each lender has non-refundable application fees, you could be out of hundreds of dollars. So, while you can research as many lenders as you like, keep the actual applications to three maximum.