Pay Day by Pay Day Tax Relief also know as Pay Day Relief Models have been used by Umbrella Companies and Employment Businesses but I have no doubt other business have used them too.
Basically the employer applies for Dispensations for Expenses and then without a valid employee claim reduces the employees pay to cut PAYE and NI costs.
There is a great example to be found on the Ross Martin website
HMRC issued a further statement in August
http://www.hmrc.gov.uk/news/news290812.htm
Its worth reading to makesure your procedures are HMRC Compliant
steve@bicknells.net