Thanks for your response
I am sure that it will come as no surprise to you, that I advise for her husband on her behalf to be honest with the tax man, - as to be perfectly honest if its her husband that is being looked into, and this is a joint account then they will accept that it was a bonus paid to her and should have no reason to ask for paperwork to back this up.
If this was paid into her account (and it just has her name on the account) then it will have no bearing on her husband - unless of course there are lots of cash deposits that have occured into her account ....
The moment you start making up where money has come from, and there is no paper trail to back a position up then its only ever going to make the situation worse for them - which I am sure you wish to avoid at all costs
If you say this is a loan - then they will ask why a cash deposit - and will then ask for evidence of the loan arrangement -
My advise she should state that it was a bonus - and that you provide paperwork to back this up - and that you delare this as the gross amount (so for example approx £5000 gross less the appropriate deductions tax of tax and NI ) then you can
1) Claim this as a legitmate business expense
2) Its one less thing for them (and you) to fret over
Anything else I offer would see me not doing my job property which you must appreciate I cannot do.