I have a few ideas on how to get money that is owed to you. First off, yes I know having a contract is best, but I am in Florida, and most people trust no one and for good reason. I am considering it though. If a customer ever calls to talk to you from work, or their cell phone, or any other #, write it down and save it. If you do an estimate for a friend of theirs, family member, ect, save that information. If they send your check in a envelope from work, save it. This way if they ever decide not to pay, you have options other than calling them, or going to their house. I have used this information in the past. Call them for the 100th time, and ask if they still work at abc, tell them you will be by on Friday to pick up the check from them there. They will pay. I have used others as well. It may not be nice, professional or other, but I got paid what I was owed. It was their choice and intent to not pay willingly, so we played the hard way. Fair is fair.