No, in most cases, a buyer obtains a mortgage after making an offer on a piece of real estate. For instance, the buyer might want to negotiate the property's sale price or ensure certain repairs are made before they proceed with financing.
The Offer to Purchase provides a timeline for the buyer to obtain a mortgage or otherwise secure financing before the offer is binding and the sale is closed.
However, a buyer may seek pre-approval for a mortgage so that they don’t make an offer that they cannot afford. In this case, mortgage lenders can identify the maximum amount that you qualify for.