How the two highest average pay gap companies are distorting reality in a different way
For the year 2019, Ash & Lacy Finishes Limited and T. Class Security Limited had the highest average hourly pay gap, both at 100%. Or to better put it, for each pound, per hour, men employees make, women make zero pence.
Even other data, such as the median pay gap, have similar disparities that there might be a reason behind it. Both companies’ numbers tell a different story that end up distorting the ranking.

A closer look to the information provided by the Gender Pay Gap Service states that T. Class Security Limited didn’t send their report in time, it was not available to look at their website at the time of the report and that their numbers may not be accurate, according to an open investigation from The Equality and Human Rights Commission.
In this case, it seems that the approach from the Gender Pay Gap Service has been to set the numbers to a default 100% pay gap until they receive a more accurate report.
Whereas in Ash & Lacy Finishes Limited, the problem lies elsewhere, mainly in the composition of the company.
A quick research shows that there are in fact 6 different Ash & Lacy companies, but the one that occupies the top spot of the report (Finishes Limited) does so because its 5 employees are all male, thus the 100% difference.
The next 8 companies on the list seem to have a more logical reason to have high average pay gap, with 7 football clubs, with high salaries to male players, and a construction company who has a predominant male working force.