Chris Johnson said:
None and I don't the want the guys work anyways, if he can't get his finances in order now good chance he has been a screw up before and will continue to be in the future, as a matter of fact when he hired you he was replacing someone probably because he didn't pay them and will now replace you with someone he will not pay at some point either
This line of thinking may be good if you are in the construction trade but property preservation is a different animal. Think of it like the difference between snooker and pool. You use balls, a table, and ques to play, but the rules are different.
If the OP is working direct with Real Estate agents (which is really hard to find/retain) and he liens the property prematurely, he will in effect end any future business with this Real Estate agent. That alone, given the nuances of the PP world, can kill his business just as fast as not getting paid.
My intent in posting my question was to influence the OP to pursue other avenues of collection of his fee's other than liens. Liens are a last resort in this business and they can get you blacklisted with other companies.