Hull Crown Court heard pleas on Tuesday from the defendants associated with construction installation companies Pink Innovations and Pink Services Ltd, which traded from premises in the Estuary Business Park on Henry Boot Way in Hull and the village of Laceby near Grimsby.
The businesses' directors Mark Anthony Stead, 48, of Croxton, Ulceby near Grimsby and Jennifer Everett, 43, of Church Lane, Ulceby, are charged with seven counts of fraud alongside David Stead, 60, of Stoke on Trent, Denise Milestone, 60, of Main Road, Brocklesby, Grimsby and Benjamin Wragg, 31, of Riverbank Rise, Barton on Humber.
The charges include fraudulent evasion of tax and VAT payments amounting to £3.5million, and cheating public revenue via incorrect income tax and National Insurance deductions and PAYE returns.
Mark Stead, who has no previous convictions, pleaded guilty to all seven counts and his defence counsel said he was resigned to 'a significant custodial sentence' though he disputes the amount of money involved.
Jennifer Everett and Benjamin Wragg admitted two of the counts, but David Stead and Denise Whitestone pleaded not guilty to three charges each and will face trial later this year.
The alleged offences took place between 2012 and 2018.