You have several elements to your question, and so let's try to address each of them individually. (Please be forewarned, as there is a a great deal of information in this answer.)
If you are a United States
citizen (or a Permanent Resident) and are married to a non-citizen, then you
have some options on how to file your US tax return, although current United
States tax laws do not make this process particularly easy.
Option # 1: You can file your US tax return as Married Filing
Separately, and
just report your own income there. TurboTax can walk you through this
process, and help you create the necessary Form 1040. But if your spouse does
not already have an ITIN number, or a Social Security Number, then this return
would have to further be printed and paper filed. If your spouse has a
valid ITIN or SSN, then the tax return would be eligible for e-filing. If
there is no ITIN or SSN for your nonresident alien spouse, then in any place where the nonresident spouse's
taxpayer ID number is required on a tax form, you would take a black or blue
pen and manually write "nonresident alien" or abbreviate as "NRA."
This is not a TurboTax restriction, but rather an IRS requirement. Thus, in order to file a tax return separately (using the MFS status), unless your spouse has either a SSN or an ITIN, then this tax return simply cannot be e-filed, and it must be paper-filed. There is no tax software in existence that will allow it, because the IRS will not.
You can also claim a personal
exemption for your spouse, when filing MFS, if your nonresident alien spouse had no gross taxable income for U.S.
tax purposes, and was not the dependent of another taxpayer. This mirrors
the similar rule for US citizens and resident aliens filing as Married Filing
Separately to claim the personal (dependency) exemption for their spouse, where
that spouse has no taxable income, is not filing a separate tax return, and is
not claimed as a dependent on any other taxpayer’s return. But, in order
to do this and claim the personal exemption, your spouse must also have a valid
Social Security Number or an ITIN.
Option # 2: You can elect to include your
nonresident spouse on your US income tax return (which may be more or less tax
favorable than Married Filing Separately); and file as Married Filing Jointly;
but you would again need to file a paper Form 1040 tax return in order to do
so. The somewhat complicated process for completing this type of tax
return is explained in detail at the IRS.gov website here:
https://www.irs.gov/individuals/international-taxpayers/u-s-citizens-and-resident-aliens-abroad...
Such a tax return (Option # 2) is probably best done by a professional tax
preparer.
If you choose Option # 1 and have any difficultly with that, then having the
tax return prepared by a professional is also an option here too.
TurboTax has a helpful
Frequently Asked Questions webpage about claiming international spouses and
children, and you may wish to look at that as well. Here is the link:
https://turbotax.intuit.com/tax-tools/tax-tips/Taxes-101/Claiming-a-Non-Citizen-Spouse-and-Children-...
Also, you can read the complete answer to a similar question that was asked
here about a year ago. There is some good information and advice in there
as well:
https://ttlc.intuit.com/questions/3089728-how-can-i-file-taxes-with-my-new-foreign-spouse-who-doesn-...
Now then, assuming that you
own a bank account or maintain other financial assets in a foreign country
(and that includes the UK as well as elsewhere), there are certain foreign
financial account reporting requirements that you must meet annually, in
addition to filing a primary tax return (Form 1040, etc.)
In fact, there are two
separate disclosure forms that may be required; each also has different
reporting rules. One is known as IRS Form 8938, and can be
attached to the relevant yearly Form 1040 tax return. The other is FinCen
Form 114, which can only be filed via the internet. The following
Internal Revenue Service webpage describes them in some detail, and provides
their dollar value reporting levels:
https://www.irs.gov/businesses/comparison-of-form-8938-and-fbar-requirements
Form 8938 is included in
TurboTax; FinCen Form 114 is not, and you may need to access that reporting
webpage separately, if your foreign financial assets total over the
limit(s). Note that you can get to the FinCen reporting internet site
through the above IRS link.
With respect to your United Kingdom income, if you do not work for the US government, then you may be able to exclude some, or all, of your foreign earned income by using IRS Form 2555 (Foreign Earned
Income Exclusion), which calculates the amount of foreign earned income and / or
foreign housing that you can exclude from US taxation; the limits are quite
generous and generally increase year over year.
In order to take advantage of
Form 2555, you must satisfy both the "Bona Fide Residence Test"
and the "Physical Presence Test." The IRS rules for
these tests are explained on Pages 1 through 3 of the Form 2555 instructions,
which can be read here:
https://www.irs.gov/pub/irs-pdf/i2555.pdf
In addition, this IRS.gov
webpage has additional examples on meeting the 330 days required under the Physical
Presence Test:
https://www.irs.gov/individuals/international-taxpayers/foreign-earned-income-exclusion-physical-pre...
Along with your federal tax return, if your last (most recent) state of residence in the United States was in a state that has an income tax, then you may also have to file a tax return there as well. It is recommended that you check with the relevant state department of revenue website for instructions on those who are living abroad. Remember that simply moving overseas does not negate state residency. The only way to change your legal domicile away from one state is to "reclocate" to another state, not a foreign country.
All of the above forms mentioned are available in the higher (paid) versions of TurboTax.
In conclusion, please keep in mind the broad IRS e-file restrictions in place for those who are married to nonresident aliens (i.e., Options # 1 and # 2 above). Paper-filing will be a necessity, unless your UK spouse has a SSN or an ITIN. Your other available choices would be to not file a tax return at all, or to e-file a false one (you cannot legally ignore your nonresident alien spouse and file as Single). However, doing so would mean breaking the law, and we would strongly advise you against that.
We hope all of this information will prove useful to you, and thank you for asking this important question.
