Posted 05 June 2012 - 07:13 AM
Seems you're focusing on the wrong question in the main (and the question itself is a bit garbled). Is the conversation something you can raise as evidence that he acknowledges the contractual obligation? Sure. (Past evidence of payment is evidence as well, and I'd like to think you can get copies of that from the seller of the property.) I'm not sure what you mean by "binding" though.
While there may be no signed copy of a lease in your possession, is there a written lease? At any rate, someone having had a verbal contract with the prior owner/landlord is fine, so long as it's a monthly tenancy or isn't longer than a year. I trust in your purchase agreement you were also assigned by the prior owner of the building an interest in any existing leases, but in general any long-term leases would run with the property regardless of owner.
As for "If I am forced to seek payment ...", presumably you already have (and that the rent is due to you vs. prior owner).
Please discuss the matter with a local real estate attorney who has experience in commercial landlord-tenant contracts.