If You Feel the Assessment is Wrong
The method of calculating child maintenance deliberately keeps the calculation simple at the first instance simply utilising self-employed and PAYE income. A significant and frequent problem occurs where the father is a Company Director and as a result his income is paid at around £7,000 to £15,000 by PAYE and the remainder of the income (usually the majority of the income) is paid by dividends. Dividends are initially ignored for the child maintenance calculation and therefore if your ex is working full time as a Company Director it could well be the case that a low assessment is likely to be due to this rule.
In order to ensure that the dividends are counted you will need to make an application for a variation which can be made very simply over the telephone but it is very important that it is chased up as the Child Maintenance Service can simply forget about these applications. There are also many complex cases where the father does not derive a significant amount of income from dividends or PAYE but instead from property, directors loans or simply diverting money to another person or just simply not take it at all and keep it in the company. For the purposes of dealing with these kind of cases and other avoidance cases (whether employed or self-employed), there is a variation system in place to try and ensure that fair amounts of child maintenance are paid by those fathers who can control elements of their income thereby reducing their exposure.
It is of course worthwhile saying that errors can also occur, I have had many cases where the Inland Revenue has produced very old income figures to the Child Maintenance Service resulting in artificially low assessments. This can happen in employed cases as well. These kind of challenges can be undertaken by means of an appeal against the decision to a Tribunal where the Child Maintenance Service has to produce the information they have utilised. If this divulges that very old information has been used then it is possible for the Tribunal to assess the maintenance itself or direct the Agency to use later tax or wage information.