As someone who has a business, Two scenarios here and I’m not sure which it is
scenario a - company a ( and the ‘friends’ relative - 100% uses his own salaried people and lets them do work , buy stuff and pays them and gets an equivalent reduction against corporation tax - only really works if it’s a company that are profitable and paying corp tax and often VAT - whereby there will be VAT ‘out’ but no VAT ‘in’ - hence a rebate or an offset if VAT due in general
scenario B - company A uses contractors for jobs from company B ( who said relative works for) and company B are sending in inflated invoices to company A to cover off work at Ops ‘friends’ house -
company A if in profit may not actually care , if they could do with a deduction against corporation tax- however almost certainly wouldn’t approve if they knew it was going on - but if they were on a fixed price job presumably company A were ok with the quote . If it’s inflated they could always have gone elsewhere where they aren’t fudging invoices to fix relatives places.
either way OP, it’s annoying but yes it does happen.
it’s only really fraud if all within company a if it’s ’kept In the quiet and someone hasn’t approved it’
in the other scenario it’s not fraud as such if company A accepted fixed price quote from company B - it is however fraud if company B are charging billable time and supplies and thenusing them on a job not costed for and billable for - but the fraud is against company A by company B
either way I wouldn’t interfere-