Thanks for your question, I am Sam and I am one of the UK tax experts here on Just Answer.
How long has your wife been resident in the UK - as at this stage you should either be declaring it - or claiming the remittance basis (where the income does not enter the UK) but this does see a loss of UK personal allowances (which are worth £11,000 x 20% = £2200) which would be relevant if there is UK income arsing for them to be utilised against, on which you advsie there is.
But as this is in excess of £2000 these are the two options and I should advsie that when your wife has been resident for 7 out of the last 9 years, then also a remittance basis charge arises, so lets see how best to take this forward for your wife
So when did your wife arrive in the UK AND how much is her annual income (approx)
Thanks for your response
Then this income should have either
1) declared as worldwide income from 2001 (its from the date she began to reside in the UK not the date of permanant residency) OR
2) Fallen within the remittance basis
But either way your wife should have registered for self assessment with HMRC and whilst for the first 6 years she could claim remittance basis - as this will see the loss of personal UK tax allowances which will see tax becoming due on any incomes that arose within the UK from that date.
However from the time she has been resident in the Uk to the 7th year, then not only does claiming the remittance basis see a loss of entitlement to UK personal tax allowances, it also sees a remittance basis charge (which starts at £30,000 a year) so my advsie is
Make a full disclosure to HMRC back to the year this US income commenced (or from 2001if it commenced prior to this) as this will mitigate the penalties and interest charges far more than not making a disclosed
And start this by amending the tax returns filed since the self employment began by adding in a foreign income page and then writing into HMRC re the earlier year disclosures
Let me know if I can assist further, or if you have all that you need, then it would be appreciated, if you could rate me for the level of service I have provided , or click accept