HMRC do of course know about this problem and we are informed it is top of the list of things to be fixed (that means that there are other things which need to be fixed!).
But just because tax payers will receive a refund twice does not mean they can succumb to the temptation of not telling HMRC that this has happened. In those instances tax payers and their advisors must inform HMRC because HMRC believe that if you are retaining money that you know you are not entitled to then this is theft under the Theft Act 1968.
I am sure you the reader will join my sentiments when I say that I am not sure whether I should laugh or cry!
By Henry Ejdelbaum