I agree - accept what they sent and then see if you can work out a payment plan. Partial payment is better than none, and shows some intent to pay. My experience is that there are people who struggle to pay, and people who have no intention of paying. The fact that they sent partial payment is a good sign. We have had some people who agreed to a payment plan after being threatened with a notice of claim. We have also had people who never contacted us in response to our offer to set up a payment plan, but who started sending in payments whenever they could, and eventually got caught up. We gave them the benefit of the doubt and did not file the Notice of Claim, but told them that as long as they were showing an effort to pay, we'd hold off on it - but that if payments stopped, we would have to file. As of a few years ago we had five long-term non-payers. We are now down to just one, who has never responded to us at all, other than just once accepting a certified letter. Town records show that he never pays his property taxes either, until the town sends him a lien.