Hm. Interesting.
When we bought the Cottage, there was an existing tank with propane still in it. We didn't pay for it at closing, apparently the PO forgot about it and since he was from NYC I imagine his lawyer didn't think about the fact that it might exist (he also filled out the paperwork stating it was on public sewer, and we have septic). So, we decided not to ask about a contract, etc, lest he realize he should get a credit for the remaining LP. Since we don't use it for heat, we haven't used all that much-we did blow through a bunch when 1) we tried to use the oven on the stove that was here which didn't work properly and ate about 20% of it between 2 or 3 uses and 2) we hooked up a small blue flame heater in the mechanical area but put the thermo probe too close to concrete which caused it to run too much and ate about another 20% before we sussed out the problem with it. All in all, we have been hanging at about 20% full most of the summer. I couldn't say off hand how big the tank is. We never signed a contract with the company on the tank, and obviously haven't paid for a refill. I wonder if they are going to up and take the darn thing one day, lol. We planned on replacing it with two 100 pounders in sequence (so when one runs out the other kicks in) so we wouldn't mind actually, except I'd love to wait until we use up the rest of the free stuff!!