Barclays has decided to review its sales of tax products as “some of them may no longer be appropriate”.

As I've already noted, there are lessons to be learned from this. The first was that, as Barclays has now learned to its cost, tax avoidance does not pay.

The second could be described as the inverse of that first lesson: it is that tax avoidance is not profit maximising behaviour.

Now, I've said that for a long time, but it's really important that a company like Barclays has realised it. This shatters, forever, the myth that it is the directors duty to minimise tax bills: it is not and Barclays are saying it is not. It's time the rest of business took note.

More to follow.