Contracted by client to perform services which an agreement was signed, contract states payment within 30 days,paid on 32nd day is breach of contract?

To answer your first question if payment on the 32nd day would constitute a breach of contract. The answer is yes. The agreement was to make a full payment within 30 days. Any deviation from that constitutes as a breach. However, although the other party technically breached the contract, they ended up making a full payment after 2 days. Thus, minimizing your damages. I believe you indicated that you had to pay for the overnight delivery of their payment. If so, that can go towards your damages. To answer your second question regarding the other party deducting from their payment for the following month, this question is a bit harder to answer. I am confused of whether they are claiming the contract is null and void or if you are. If you are claiming they breached the contract and therefore the contract is now null and void, by accepting any payment, you are implying the contract still stands. However, if the other party is claiming the contract is null and void and they are still sending you a payment, I don’t understand why they would do that. Perhaps more facts will help. But one thing I would like to state is that any modification to any agreement cannot be done by only one side, most of the time. Contracts usually contain a clause that states that if a modification of the current agreement is to be made it can only be made if all parties agree. Further, usually the modification must be in writing. I hope I have helped. I don’t think I was able to answer your question to my fullest ability due to the confusion that arose. If you would like to discuss your situation in more detail, feel free to contact me.