Consulted different banks Spanish like La Caixa, Solbank, Caja Murcia, Bankinter, etc., they have answered the same: NIE is required in the initial steps of the mortgage process.
In other words: NIE number is required to apply for the mortgage, so, the process cannot start without it.
It was common in the past that buyers were obtaining their NIE just before completion. It was relatively comfortable because they could leave this step to be done at the end of the process, just organizing their visit to Spain a couple of days before completion, in order to have enough time to get this document for the sale. Buyers could, meanwhile, applying and processing their mortgages, because NIE was not required from banks till completion.
But, now, as banks are requiring the NIE number to start the application of their mortgages, buyers who did not obtain this document in their previous visit to Spain, they must come expressly just to get this document.
Another option is to try to obtain the NIE in the Spanish Consulates placed in their countries of origin, but this way uses to take long time. So, these buyers are now forced to come to Spain just to obtain their NIE numbers to be able to apply for their mortgages.
TLA recommends buyers that, when coming to Spain to visit properties in which they could be eventually interested, to make the best use of this visit to obtaining the NIE numbers. They could obtain assistance from the local agents, or from their lawyers, about how to get them, and to have this step sorted in this first visit. This will avoid problems in the forward steps of the process.
For more information, please, do not hesitate to contact us, we will be delighted to help you.