So from what I understand, the UK tax year runs from April to April. However, the US tax year runs January-December. Is there anyway to retrieve documentation on how much UK taxes were paid for a certain amount of months? My husband will soon be working in the UK, and he is a green card holder, so he is still subject to US tax. I will be joining him in January, and working up until then. So when I file my 2017 taxes, I need to state his income as well as the tax he paid, so we won't be double taxed. Would we still be eligible for the automatic extension for overseas filers even though I spent the entirety of the tax year in the US?