There have been plenty of figures bandied around as to how many Code Numbers are wrong as a result of errors made by the tax authorities. Whatever the exact figure may be, it is clearly significant and shows no sign of being reduced to any meaningful degree.

One annoying aspect of this is that if you have more than one job, the policy is to bring into account ALL taxable benefits within the main job's Code Number, even where the benefit actually relates to a different job. That seems bizarre and surely itself causes queries to be raised.

Of arguably more importance is that HMRC have now admitted that their PAYE coding processes cannot identify items which have been included in a previous Coding but which should later on be removed. The prime example of this is, say, where you have private health cover provided by your employer and the tax payable on that benefit is collected by reducing your Code Number. If that benefit stops HMRC will be aware of that as the annual form P11D will simply not show any entry for it. However, HMRC will not automatically increase your Code Number and we have to tell them what to do ourselves. Please therefore keep us right up to date when your remuneration package changes in any way. Not surprisingly, HMRC do seem able to reduce a Code Number when they find out from the form P11D that a benefit has increased in value!