We are a mitigation company that frequently performs work for property managers of multi-family buildings. Can we file a lien if our work authorization is signed by a property manager and not the building owner?
Yes, you can do that. The lien is against the property/its owner. If you aren't getting paid, you'd have a breach of contract case with the party that hired you and a potential lien--assuming you have complied with all the lien precursors.