That's very interesting. I'm officially self-employed, my income is not high - well, not for the last few years - and HMRC interest in my accounts is not running at the levels it might be.

But I also wonder about incompetence and under-staffing. I don't suppose the pay is particularly good for minion-level inspectors, the different parts of the system - corp tax, personal tax, PAYE, and VAT - don't seem to talk to each other, and although fierce powers are available, it's not obvious how often they're used.

And newer parts are broken. I had a completely spurious demand for £2.4k of back PAYE a couple of weeks ago, from the new RTI system. It seems to have decided to ignore the submissions and pick a random estimate.

I solved it with a phone call. But I doubt I was the only victim.

I wonder how many people paid it, and how much cheaper and quicker it is to send out threatening 'estimates' than to handle real numbers.