The High Income Child Benefit Charge is worked out week by week. For each week, the charge falls on whoever has the higher adjusted net income for the whole tax year out of the claimant and anyone who was their partner throughout that week, provided that person is over the £60,000 threshold. When a couple separate or a new partner moves in, each person pays only on the Child Benefit for the weeks that fall to them, using their own income for the full year.

Tax investigation insurance from £108.75 a year (£9.06 a month).Pays up to £100,000 of your accountant's fees if HMRC opens an enquiry. No excess. Buy online in a few minutes.

See my price in 2 questionsHow the cover worksAccountant? Offer cover to your clientsor call 01795 841 310

Why does the charge follow weeks rather than the whole year?

Child Benefit is a weekly benefit, and the charge in sections 681B to 681H of the Income Tax (Earnings and Pensions) Act 2003 mirrors that. Section 681H defines a week as seven days beginning with a Monday, and a week belongs to a tax year only if its Monday falls in that year. By that definition the 2026 to 2027 tax year contains 53 weeks, because 6 April 2026 and 5 April 2027 are both Mondays. HMRC’s return notes for 2025 to 2026 confirm the same approach: that year ran from the week beginning Monday 7 April 2025 to the week beginning Monday 30 March 2026, a total of 52 weeks.

Section 681B sets two conditions, tested separately for each week:

  • Condition A catches the claimant, but only if nobody who was their partner throughout that week has a higher adjusted net income for the year.
  • Condition B catches someone who was the claimant’s partner throughout the week and whose adjusted net income for the year is higher than the claimant’s.

In both cases the person charged must have adjusted net income above £60,000 for the year. The basics of the charge are covered in our guide to the High Income Child Benefit Charge; this page deals only with what happens when the household changes during the year.

Who counts as a partner for the charge?

Section 681G treats two people as partners if they are married or civil partners and are not separated under a court order or in circumstances likely to be permanent, or if they are not married but live together as if they were. GOV.UK adds that short periods apart, such as a hospital stay or working away from home, do not count as separation. So a couple who split for a few weeks and then reconcile have usually never stopped being partners, while a couple who part for good stop being partners from the date of the permanent separation, even if a divorce follows much later.

Run an accountancy or bookkeeping practice? Solar Protect runs fee protection schemes for practices, so the cost of dealing with an HMRC enquiry into a client is covered rather than written off.

See how our accountant schemes work or call 01795 841 310.

What happens when a couple separate during the year?

GOV.UK says the charge applies from the date you move in together to the date you permanently separate or the Child Benefit stops. The explanatory notes to Finance Act 2012, which introduced the charge, give the same answer: if the couple break up, the higher earner is liable only from 6 April to the week in which the break up occurs.

The wording of section 681B adds a detail that is easy to miss. Condition B only applies to a partner who was a partner throughout the week. In the week in which the separation happens, the former partner was not a partner for the whole week, so that week falls under condition A and is charged on the claimant, if the claimant’s own income is over the threshold. After the separation, the claimant is the only person who can be charged on their Child Benefit, again only if their own adjusted net income exceeds £60,000.

What happens when a new partner moves in?

The same rule works in reverse. The Finance Act 2012 notes say that where a couple start living together and Child Benefit is already being paid, the partner with the higher income is only liable for the weeks from the date they start living together to the end of the tax year. The new partner’s adjusted net income is still measured for the whole tax year, including income earned before the move, because sections 681B and 681C refer to adjusted net income “for the year”. A new partner who earned most of their income before moving in can therefore still be the higher earner for the weeks they spend in the household.

If both partners already claim Child Benefit for their own children, the higher earner is charged on both claims for the weeks they live together: their own claim under condition A and the other partner’s claim under condition B. Where both partners have exactly the same income, the 2012 explanatory notes say the charge rests with the claimant.

How is each person’s charge worked out?

Section 681C applies a percentage to the Child Benefit for the weeks that fall to each person. The percentage is 1% for every £200 of adjusted net income above £60,000, capped at 100%, so the whole amount is payable once income reaches £80,000. GOV.UK confirms these figures apply from the 2024 to 2025 tax year. The total of the weekly amounts, the percentage and the final charge are each rounded down to a whole number.

Two people can therefore pay a charge on the same claimant’s Child Benefit in one tax year, each on different weeks and each at their own percentage. Adjusted net income is explained in our guide to adjusted net income.

What does that look like with real dates?

Illustration only. Priya claims Child Benefit for one child at the 2026 to 2027 rate of £27.05 a week. Her own adjusted net income is £30,000, so she is never charged herself.

  • She lives with Tom, whose adjusted net income for the year is £85,000, until they permanently separate on Wednesday 7 October 2026. Tom was her partner throughout the 26 weeks beginning 6 April to 28 September 2026. Those weeks total £703.30, rounded down to £703, and at 100% Tom’s charge is £703.
  • The week beginning Monday 5 October falls to Priya because Tom was not her partner throughout it. As she is below the threshold, nobody pays on that week, and the same applies to the 12 weeks she lives alone.
  • Sam moves in on Monday 4 January 2027. His adjusted net income for the whole year is £66,000. The 14 weeks from 4 January to the week beginning 5 April 2027 total £378.70, rounded down to £378. His percentage is (£66,000 minus £60,000) divided by £200, which is 30%, so his charge is £113.

How do you report a split year on the tax return?

HMRC’s notes to the SA100 return for 2025 to 2026 tell you to enter in box 1 of the High Income Child Benefit Charge section the Child Benefit you or your partner received for the year. Where you and your partner started or stopped living together during the year and their income was over the threshold and higher than yours, you enter only the Child Benefit you received while you lived alone, and your partner enters the amount received while you lived together on their own return. The notes say they will need to be registered for Self Assessment to do this. Box 3 is for the date payments stopped if all Child Benefit ended during the year.

If you pay the charge through your tax code instead, GOV.UK says you must tell HMRC if you separate, using the online service or by contacting HMRC, and your tax code will be adjusted. To pay through PAYE you need the National Insurance number of any partner who received Child Benefit in the last tax year and the dates of those relationships. See paying the charge through PAYE for the conditions.

What if your former partner will not tell you their income?

GOV.UK allows you to write to HMRC to ask whether your partner or former partner gets Child Benefit or has a higher income than you. HMRC will only answer yes or no and will not disclose any financial details. You can ask only if you live together, or separated within the tax year you are asking about. The letter needs the tax year, your own details and adjusted net income, and as much as you know about the other person.

Which mistakes come up most often?

  • Counting a new partner’s income only from the date they moved in. The comparison uses adjusted net income for the whole tax year.
  • Treating a temporary separation as the end of the partnership, or continuing to report a partner after a permanent separation.
  • Both former partners reporting the full year’s Child Benefit, or neither reporting the weeks they shared.
  • Forgetting the week of separation or moving in, which belongs to the claimant rather than the partner.
  • Ignoring the charge because the claimant earns less than £60,000. A new or former partner may still owe it, and the steps to put that right are in our guide on what to do if you missed the charge.

Anyone who expects to be over the threshold for most of the year can also consider whether to stop Child Benefit payments while keeping the claim in place for National Insurance credits.

If HMRC opens a check into your return, tax investigation insurance pays your accountant’s fees. Solar Protect cover pays up to £100,000 with no excess; it never pays tax, interest or penalties. Read how our cover works or get a quote.

Related Accountapedia entries

Sources

Reviewed by Christine Anderson, Broker, Solar Protect. Last reviewed 24 October 2026. Part of Accountapedia, the Solar Protect guide to UK tax and accounting. This page is general information, not personalised advice.