No, it is quite normal that vendors sign power of attorney to their solicitor and do not attend the signing of title deeds at notary. We do, however, suggest that if the property is sold furnished, that personal items are removed prior to handling over the keys. Pro Tip:  Signing power of attorney to a solicitor is cheaper and faster to be done in Spain, rather than in the country of origin, as it will require to have a Hague Apostille or the document to be validated by the Spanish Consulate, apart from adding the translation costs.