Foreign income internship

[Dukray]

Thanks to everyone!

So it seems clear that I should declare this income via Self Assessment and claim all paid US tax as credit.

Now, the case is that I have never filed a tax return, so two more questions would be:

1. Should I hire an accountant, or is it a straight forward process?

2. Assuming this return will be filed after the deadline for the 2018-19 tax year, which is Jan 31st, would I be facing penalties and of what kind (e.g. for late registration/payment)? I ask because in other countries, sometimes you can "catch up" several years worth of income when filing your FIRST tax return ever, but I am not sure if something similar exists in the UK. For what is worth, I have not received any notification from the HMRC asking me to pay, so this would be a "proactive" move on my part -- does that change my situation in any way?