A commercial lessee is having a large restaurant build out done. The general contractor continues to send invoices without support, change orders without signature etc. No contract between the general contractor and property owner or lessee exists. If they GC files a lien, what would they base it off of then? And do they have an actionable lien against the property owner if the commercial lessee is who they actually are engaged in the work for? If they only have an action against the lessee, how would they seek to have that paid?
The contractor may or may not be able to lien the property owner. It will depend on what the lease says. But the lessee's interest is subject to a lien for the "reasonable value" of the labor, services and materials provided, even if there is no agreed contract price. In other words, the tenant does not get the improvements for free, even if there is no agreement on price. So yes, the contractor can record a lien for the "reasonable value" which will likely be asserted as the claimed contract price, and if the lien goes to court, it will be up to the judge or jury to decide if the reasonable value claimed is, in fact, the reasonable value of the labor, materials and services furnished.
I should add that the contractor will have to prove there was an "implied agreement" to be paid the reasonable value of labor, services and materials provided. The court would look to the parties' communications and conduct to determine if such an implied agreement can be inferred from the circumstances.