OVER THE YEARS, I've blanked much of the advice dispensed by my father. I mean, I love the guy, but he can't calculate NPV for toffee – so what does he know? But However, he did pick a useful motto from his army days (guarding obsolete tanks parked in a field near Slough – whatever happened to all the heroes, eh?). "Never volunteer" was his battle cry and... well, I have to agree. So the email – "subject: Help required!" – from the Blaminio chairman to the "Finance Resource Strategy Group" (the £2,500-a-day consultant's new name for my bit of the department) had already been deleted when, lo and behold, the message re-appeared via the FD. "FW: Help required! This is not optional, Barry." I'd been volunteered.

The chairman (TC, we call him) had agreed to take on the "book iE had been keeping" for bookkeeping for this a small but highly influtential influential charity he's involved with. Apparently this cause is of great personal interest to Prince Charles. t7, So TC, looking to the 2008 honours list, had put Blaminio's commercial expertise at its disposal. It seemed fairly run of the mill. The charity had a grant from the Lottery Commission, did a bit of trading, held an annual dinner (mostly in the, so far vain, hope that HRH would pitch up) and published a few reports and newsletters.

Alarm bells did ring when TC announced that the previous auditors had resigned over, ahem, "conflicts of interest". But the good news was that the accounts were on a spreadsheet – easy meat. TC's only real concern was that I "clarify the VAT return situation." VAT? Ha! I reckoned I had a couple of days jockeying at most. So I persuaded FD to clear my diary for a week and a half and got stuck in. Ah. Two weeks later I was still mired in the spreadsheets, fending off increasingly frantic calls from TC's office (now his PA remembers my SENT OUT WITHOUT name), a partner from the old auditor who's suddenly taken an interest, a rather unpleasant Customs & Excise "client liaison officer" (which must make Gordon Ramsey a "catering careers consultant") who keeps wanting to know where the return is – and FD, who's wondering when I'm going to start on the budget reforecast.

The problem? The spreadsheet was set up pretty well. But then the accounting firm appears to have handed it on to a succession of juniors who didn't know that VAT in a charity is complicated stuff. This one had exempt transactions, such as the members' club. It had some trading activities, such as the annual dinner, that were standard rated. And it produced various publications that were zero rated. But However, the spreadsheet was hopelessly muddled between exempt, zero and standard, with formulae randomly calculating different levels of VAT for different transactions.

The worst bit? The annual dinner invoices had been sent out without VAT applied at all. Telling TC – who happens to chair the dinner organising committee – that he was 15 per cent short on revenues for the gig was an "interesting" moment. I suggested we send out invoices to all the guests (HRH included) asking for the missing VAT element. But TC's face went from mauve to puce, which suggested he didn't think that was such a great idea. (Mind you, at least now I know what "fill" colours to use on the cells showing falling divisional margins in the next management accounts.)

By the time I'd finished recalculating several years of VAT returns, Customs were slavering at the thought of a big cheque, the Lottery boys were asking tricky questions and the charity faced financial ruin. Before it all got out of hand, TC called the inaugural meeting of Blaminio's CSR committee (membership: him and the Ell). Result? A large proportion of the year's enter¬tainmententertainment budget was reallocated to the charity. By chance, the amount exactly matched my carefully worked out VAT balancing charge...

Even so, I reckon TC can forget his gong for the foreseeable. I did think about sharing my dad's military wisdom with him. But- but you don't want to push these things, do you?