That's it in a nutshell from RedOnion. The solicitors absolutely WILL check, they've no choice but to do so, and the outstanding charge has to be paid. However, there remains a discretion if your friend can make a case that there was any fault on the councils side at the time eg, unanswered queries from the owner, wrong advice given, that sort of thing. He would want some evidence to back up any case made. However, this was a long time ago, councils' records and paperwork won't always be readily available, staff will have moved on and NPPR isn't really a big issue that they care too much about. So if he can raise any sort of argument at all, it's probably worthwhile pursuing it. If he makes a fuss, I suspect they'll do a deal and agree a lower figure just to close the file.