Is Cash in Hand Counted as Salary

I earn a modest salary and my partner is officially on about 25% of my salary. However, she earns a further £18,000 a year in cash by cleaning, selling on eBay, car boot sales etc. As she's paid cash in hand, there is no formal record of this employment. There are however banking records of all this money being paid into our joint account.

Is this "income" taken into account when calculating a maintenance allowance or Clean Break fee? It would seem very unfair otherwise as this effectively takes her salary up from 25% to 50% and would make a considerable difference in the maintenance allowance.

Does she declare the income and pay tax on it?
Are you talking about child or spousal maintenance? child maintenance has a set formula based on the income of the non resident parent.
Spousal maintenance is increasingly unusual. It is based on clear need and ability to pay. Any universal credit is reduced £ for £ so if benefits are part of the mix this has to be considered.

Hadenoughnow

No, she's not declaring it(!) I said that is not a good thing to be doing.
So are clean breaks now more commonplace? I don't see any online calculators for clean breaks. Can anyone point me to any please?

Clean breaks are the preferred outcome unless they can’t be achieved.

You need to post details of ages, incomes, children and all assets for someone to comment.

3 children all over 18. Total assets £1.5m. My salary £70K, her salary £25K + her undeclared £18K. Thanks.