Lenders are the strictest party in the transaction. Most banks and credit unions will only fund a mortgage signed under a power of attorney if their own legal department pre-approves the specific document, so raise it before an offer is written, not after, and budget legal fees of $800 to $1,500 for the extra review.
Title also has to cooperate. A purchase signed under a power of attorney is registered through Information Services Corporation, and the document itself, along with proof it has not been revoked, becomes part of the closing file your lawyer assembles.
Start this conversation with your lawyer and your lender before you make an offer, since a power of attorney that is not pre-cleared can delay or derail a possession date. Get your hand-reviewed valuation from Joel Dyck.