A US citizen living in the UK can usually claim the US child tax credit (opens the official IRS page in a new tab) for a child who is a US citizen, is under 17 at the end of the year, lives with them for more than half of it, and has a Social Security number valid for employment. From tax year 2025 the parent needs a valid number too. Living abroad does not bar the claim. The refundable part, the additional child tax credit, is not available in a year in which the parent claims the foreign earned income exclusion.
This post is for American parents in the UK, including those married to a British spouse, who want to know whether the credit is open to them and what stands in the way. It goes further than the short paragraph on children in our guide to US and UK tax returns for Americans in the UK: which children qualify, the number rules that changed for 2025, why the choice between the exclusion and the foreign tax credit matters so much here, a worked example, and what to do about earlier years.
Can you claim the child tax credit while living in the UK?
Yes, if you and the child meet the tests. Nothing in the qualifying child rules requires the family to live in the United States. The child must have lived with you for more than half the year, and a home in Leeds meets that test as well as one in Ohio.
The credit is claimed on Form 1040 with Schedule 8812 (opens the official IRS page in a new tab) attached. It has two parts. The first reduces US income tax and cannot take it below nil. The second, the additional child tax credit, is refundable, so it can produce a payment from the IRS even where no US tax is due. For most American families in the UK the second part matters more, because UK tax relieved by the foreign tax credit often leaves little US tax for the first to reduce.
The amounts were raised by legislation enacted in 2025, and the maximum credit for each child is higher for 2025 than it was before. The refundable part has its own, lower cap per child, and it builds up with earned income above a floor. The full credit is available below an income limit that is higher for joint filers, and it is reduced above it. The IRS page on the credit and the Schedule 8812 instructions (opens the official IRS page in a new tab) give the current figures.
- Under 17 at the end of the tax year
- Your son, daughter, stepchild, eligible foster child, sibling or a descendant of one of them
- Lived with you for more than half the year, with exceptions for temporary absences
- Did not provide more than half of their own support
- A US citizen, US national or US resident alien
- Claimed as your dependent and holding a Social Security number valid for employment
Which children qualify when the family lives abroad?
A child who is a US citizen generally qualifies on citizenship, wherever they were born. A child who is not a US citizen, US national or US resident alien does not qualify for the child tax credit, even if they meet every other test. For a family settled in the UK, citizenship is usually the question that decides the claim.
Publication 501 (opens the official IRS page in a new tab) notes that children are usually citizens or residents of the country of their parents, and that a child of a parent who was a US citizen at the time of the birth may be a US citizen even if the other parent was not and the child was born abroad. Whether citizenship actually passed depends on how long the American parent lived in the United States beforehand, as our guide explains. Settle that first, because it also decides whether the child can get a Social Security number.
The Form 1040 instructions apply a wider citizenship test for dependents, which admits residents of Canada and Mexico, and a narrower one for the credit. A British child living in the UK passes neither. Publication 501 has an exception for a child legally adopted by a US citizen who lived with them all year, which can make the child a dependent. Where a child is a dependent but cannot be used for the child tax credit, the credit for other dependents may apply instead. It is not refundable, so it rarely helps a family whose UK tax already covers its US liability.
What do the 2025 Social Security number rules require?
From tax year 2025, the child and the parent claiming the credit both need a Social Security number. The Schedule 8812 instructions define a valid number as one that is valid for employment and issued by the Social Security Administration before the due date of the return, including extensions. A number issued after that date does not count.
On a joint return only one spouse must hold a valid number, and the other needs a number or an ITIN issued by the due date. That matters to an American married to a British spouse. Filing separately, which is the usual status in that case, the American's own number is enough. Filing jointly under the election to treat the non-US spouse as resident, the British spouse needs at least an ITIN (opens the official IRS page in a new tab), applied for on Form W-7. The trade-offs are set out in our post on filing status with a non-US spouse.
The due date rule makes timing important for a child born late in the year. Publication 501 suggests requesting an extension on Form 4868 if the number has not arrived in time. For a parent abroad the return is already due by 15 June under the automatic extension, and a Form 4868 extension runs to 15 October. An adult citizen who has never had a number faces a longer process, covered in our post on getting a Social Security number from the UK.
Why does the foreign earned income exclusion block the refundable part?
Because the rules say so directly. The Schedule 8812 instructions state that a taxpayer who files Form 2555 cannot claim the additional child tax credit. The part of the credit that reduces tax remains available, but with UK salary excluded there is often little US tax left for it to reduce, and the refundable part is the part that is lost.
Publication 54 (opens the official IRS page in a new tab) puts the same rule the other way round. A taxpayer who claims the foreign earned income exclusion, the foreign housing exclusion or the housing deduction cannot take the additional child tax credit in the same year. If an exclusion was chosen in an earlier year and the additional child tax credit is claimed in a later one, the earlier choice is treated as revoked, and a revoked exclusion cannot generally be chosen again for five years without IRS consent.
That is one reason we rarely start from the exclusion for a family in the UK. UK tax rates are generally higher than US rates, so the foreign tax credit on Form 1116 often removes US tax on UK salary just as well, keeps excess UK tax as a carryover, and leaves the refundable child credit open. Our post on the foreign tax credit or the exclusion in the UK compares the two in full. The answer still depends on the facts.
How does the credit work alongside the foreign tax credit?
The foreign tax credit is applied first, and the child tax credit then reduces whatever US tax is left. Where UK tax has already removed the US tax, the non-refundable part has nothing to work on, and the unused amount may be claimed as the refundable additional child tax credit, up to its own cap and subject to the earned income rules.
The order comes from the forms. The credit limit worksheet in the Schedule 8812 instructions subtracts the foreign tax credit (opens the official IRS page in a new tab) and certain other credits from the tax on the return before measuring how much child tax credit can be used. The instructions then say that where the credit allowed exceeds the amount used, the additional child tax credit may be available. Income excluded under a tax treaty is left out of the earned income used in that calculation.
Take a US citizen employed in Leeds, married to a British teacher, filing married filing separately. Both children were born in the UK, are US citizens through her and hold Social Security numbers. Her salary is taxed under PAYE, and she claims the foreign tax credit on Form 1116. The UK tax on her salary covers the US tax, so her US income tax comes to nil and the non-refundable credit has nothing to reduce. Her earned income is above the floor, so Schedule 8812 can produce an additional child tax credit for each child, paid as a refund. Had she filed Form 2555, the return would show nil tax and no refund.
- Child tax credit: reduces US income tax, cannot take it below nil
- Additional child tax credit: refundable, capped per child, needs earned income above a floor
- Credit for other dependents: non-refundable, for dependents who fail the child tax credit tests
- Form 2555 filers: the refundable part is not available in that year
What if you missed the credit in earlier years?
Earlier years can often be reopened. A missed refundable credit is claimed on an amended return, and the IRS generally allows a refund claim within three years from filing or two years from payment, whichever is later. Years before 2025 follow the rules in force for those years, so check the instructions for each year rather than applying the current ones.
An amendment has to respect the exclusion rules. Swapping the exclusion for the foreign tax credit in a past year, so as to reach the refundable credit, is a revocation, with the five-year consequence described above. Our post on revoking the foreign earned income exclusion explains how that is done on Form 1040-X and why the years are worked through in order.
Families who have not filed at all start with the missing returns. The streamlined filing route is the usual way back for people whose failure was not wilful, and late returns can include the credit where the conditions were met, subject to the time limits on refunds. A claim must be correct. The instructions warn that a credit claimed through reckless or intentional disregard of the rules leads to a ban on claiming for a period of years, and a longer one for fraud.
We check eligibility, numbers and exclusion history together in individual tax return preparation. For everything else an American family in the UK files, return to the guide to US and UK tax returns for Americans in the UK.
General information, not advice. The right answer depends on your circumstances and the tax year concerned.
