You can say a lot, by saying nothing at all!
When a Customer calls or in response to a request, says they cannot pay the full amount today, pause on occasion before you ask them to explain or begin your negotiations.
If you are a seasoned collector, the odds are you know exactly what you’re going to say next. However, when you pause (at least a count of five, and it’s great if they ask, ‘are you still there’, it gives the debtor the impression that you are going, somewhat reluctantly, into uncharted waters.
Also, if they have said they can’t pay the full amount due, NEVER say, ‘how much can you pay’. It puts them into the driver’s seat. You are better off with “how much are you short of” and quote the full amount due.
Granted, there may be an occasion when you ask, “how much are you short of the $1,500 and they will answer, $1,500”, however you will be getting much closer to the amount you want – the full balance due, than if you ask, “how much can you pay”. Another variation is “how much are you short of” and then again – quote the full balance.