The biggest mistake in NY is the Statute of limitations on filing We have 4 months (on a residential property) to file the lien with the county. Usually this time period is eaten up by half hearted collection attempts. As far as all other procedural things they are straight forward. The only other quasi speed bump, that a suprising number of contractors get caught on is Conscent. You must have permission of the property owner, not a tenant or family member, to do the work in order to be entitled to file in Lien. In the event of a landlord/tenant siuation (mostly commercial settings i.e. store fronts), a short authorization to do improvements form signed by the Landlord is good practice before begining. With regards to family members, Some states (NY being one of them) have construed certain family members to be agents of the property owner, therefore allowing a lien to be placed. For a bit more info on Mechanic liens see the same title forum listed in the General discussion area.