One twist, as most practitioners have caught onto this - though I have done this for years- is that in accounts there are often accruals/prepayments where the amount in accounts straddle two accounting periods.
Where you have annual contracts especially chunky ones like insurance, if the accrual starts in the year prior, then the rule of thumb- get it out within 6 months after the year end- is out the window.
If say you have a March Annual payment with a December year end, the 3 months into the current period means that they have to be notified or demanded within 3 months of the current year end, not 6, as they were incurred more than 18 months prior.
Based on the information posted, I offer my thoughts.Any action you then take is your liability. While commending individual effort, there is no substitute for a thorough review of documents and facts by paid for professional advisers