HMRC confirmed in its August 2026 Agent Update that Child Benefit information is now being pre-populated in online Self Assessment tax returns using information already held by HMRC.

The change is designed to help taxpayers calculate and report the High Income Child Benefit Charge correctly. It should make online filing easier, but pre-populated information still needs to be reviewed rather than accepted automatically.

What is the High Income Child Benefit Charge?

The High Income Child Benefit Charge can apply where an individual or their partner receives Child Benefit and one partner’s adjusted net income exceeds the relevant threshold. The charge is assessed on the higher earner, even if the Child Benefit is paid to the other partner.

Adjusted net income is not always the same as salary. It can include employment income, profits, rental income, dividends, savings income and other taxable amounts, with certain deductions and reliefs taken into account. Pension contributions and Gift Aid donations can therefore affect the calculation in some circumstances.

What has HMRC changed?

When an online Self Assessment return is prepared, HMRC may now insert Child Benefit information it already holds. This is intended to reduce omissions and help ensure that the charge is calculated and paid on time.

The development is particularly useful where the taxpayer may not have the exact annual Child Benefit figure readily available. However, it does not transfer responsibility for the return to HMRC. The taxpayer remains responsible for submitting a complete and accurate return.

Why the figure still needs checking

HMRC’s information may not reflect every change in family circumstances immediately. The pre-populated amount should be checked where:

• Child Benefit started or stopped partway through the tax year.
• The claimant changed, or the child moved between households.
• A partner moved in or out during the year.
• Payments were opted out of while entitlement remained in place.
• The taxpayer’s income changed materially or included bonuses, dividends or rental profits.
• Pension contributions or Gift Aid donations affect adjusted net income.

Receiving payments and retaining entitlement are different choices

Some higher-income families choose not to receive Child Benefit payments to avoid having to repay them through the charge. That does not necessarily mean the underlying claim should be cancelled.

Maintaining a claim can protect National Insurance credits for the claimant and can help ensure a child receives their National Insurance number automatically. Families should consider the wider position before ending a claim altogether.

What records should be provided to your accountant?

When preparing the 2025/26 tax return, tell your accountant whether anyone in the household received or claimed Child Benefit. Provide details of the claimant, the children covered, any periods when payments stopped and any relevant changes in partners or living arrangements.

It is also important to provide complete income information. A taxpayer whose salary appears to be below the threshold may still be affected after bonuses, benefits, dividends, rental income or other sources are included.

Do not assume pre-populated means correct

Pre-population should reduce administrative work, but it is a starting point rather than a guarantee. Checking the amount before submission is much easier than correcting a return later, dealing with interest or responding to an HMRC enquiry.

If you are uncertain whether the charge applies, ask for a calculation before filing. That allows adjusted net income, reliefs and household circumstances to be considered together.

Official Sources

• HMRC Agent Update 146: Child Benefit information pre-populated in Self Assessment returns
• GOV.UK: High Income Child Benefit Charge