UK IHT100 Forms 2026/27 — New Accounts and Deadline

HMRC stopped processing previous versions of the Inheritance Tax 100 (IHT100) forms after 31 August 2026. If a trustee or other taxpayer sends an old version after that date, HMRC says it will not be accepted and the sender will be asked to resubmit the correct version.

This is a form-version and submission-risk change. It does not create a new Inheritance Tax charge, change the rate of tax, or mean that every trust must file an IHT100. The first question remains whether the particular lifetime transfer or trust event requires an IHT100-series account. If it does, the next question is which current standalone account and schedules match that event.

What changed with the IHT100 forms?

HMRC moved away from one modular IHT100 format. From August 2024, the form system was replaced by a set of standalone accounts linked to the type of chargeable event being reported. HMRC's later reminder is important for anyone still holding an older template: submitting that previous version after 31 August 2026 can result in rejection and a request to file again.

The change is easy to misunderstand. “Use the new IHT100 forms” does not mean “file an IHT100 for every trust” and it does not mean that a form submission automatically proves a tax liability. It means that, where an IHT100-series account is required, the account should be the current event-specific version published by HMRC, with the required schedules and evidence.

When might an IHT100-series account be relevant?

The IHT100 suite is generally associated with lifetime transfers and chargeable events involving settled property. Examples in HMRC's manual include:

This is an orientation table, not a substitute for HMRC's form-selection instructions. The same family of forms can involve different supplementary schedules, valuation evidence and relief questions. A lifetime transfer that later becomes relevant because of a death may also have a different reporting route from an event occurring during the beneficiary's lifetime.

What to do if you have an old IHT100 ready to send

IHT100 is not the same as an IHT400 death account

The IHT100 suite is mainly a route for lifetime and trust chargeable events. A death estate normally has a separate Inheritance Tax account process, commonly involving IHT400 or the relevant excepted-estate and probate rules. Do not select an IHT100 merely because the estate includes a trust or because someone has mentioned a ten-year charge.

The correct route can depend on the relationship between the deceased, the trust, the beneficiary's interest and the date of the event. For example, HMRC's manual distinguishes an interest ending during a beneficiary's lifetime from an interest ending because the beneficiary has died. Use the current event-specific guidance and obtain specialist advice where the trust history or death connection is complicated.

Evidence to assemble before completing the account

The account is easier to review when the underlying evidence is assembled first. Depending on the event, this may include:

• the trust deed and later variations;
• the event date and the reason the chargeable event occurred;
• a schedule of trust assets, liabilities and ownership interests;
• independent or supportable valuations for property, shares, businesses or other assets;
• previous gifts and transfers relevant to the calculation;
• details of beneficiaries, trustees and any interest in possession;
• relief and exemption evidence, including the basis for any claim; and
• correspondence, payment references and earlier IHT accounts.

Do not fill gaps with estimated values simply to get past the form. The treatment of a valuation, liability, relief or excepted event can change the account, the tax due and the supporting schedules required.

Payment and reporting are separate checks

Submitting an IHT100-series account and paying Inheritance Tax are connected but separate compliance tasks. The event may require a payment by a particular date, and interest or penalties may apply if the obligation is not dealt with on time. The form instructions and HMRC's current payment guidance should be checked for the event rather than applying a generic trust deadline.

An account can also be required even when the final tax outcome is reduced by reliefs or exemptions. Conversely, the existence of a trust does not alone prove that an IHT100 is needed. Keep the calculation, the reason for the reporting route and the evidence supporting any no-tax or reduced-tax conclusion.

Frequently Asked Questions

Evidence and decision checks

A reliable uk iht100 new forms 2026 27 review starts by fixing the tax year and the date on which the relevant event happened. Record the person's or business's status, the income or transaction category, the amount before tax, tax already withheld, and any election or claim being relied on. Do not combine a headline figure with a final liability: the result can change when another income source, a payment date, an ownership interest or a qualifying condition is added.

Keep the source documents behind every important input. Depending on the subject, that may include payslips, invoices, bank statements, contracts, provider statements, travel records, HMRC notices, payroll submissions, valuations or correspondence. Where an amount is apportioned, write down the method and retain the underlying total. If a correction is made, preserve the original figure and explain the reason, date and evidence for the replacement.

Before relying on the result, check the current official guidance for the same tax year and jurisdiction. Distinguish enacted law from a consultation, draft measure, announcement or future proposal, and record the effective date. Reconcile the final estimate to the relevant return, payroll record or HMRC account. A calculator or explanatory guide can support a decision, but it cannot replace the eligibility test or the official filing and payment process.

Evidence and decision checks

A reliable uk iht100 new forms 2026 27 review starts by fixing the tax year and the date on which the relevant event happened. Record the person's or business's status, the income or transaction category, the amount before tax, tax already withheld, and any election or claim being relied on. Do not combine a headline figure with a final liability: the result can change when another income source, a payment date, an ownership interest or a qualifying condition is added.

Keep the source documents behind every important input. Depending on the subject, that may include payslips, invoices, bank statements, contracts, provider statements, travel records, HMRC notices, payroll submissions, valuations or correspondence. Where an amount is apportioned, write down the method and retain the underlying total. If a correction is made, preserve the original figure and explain the reason, date and evidence for the replacement.

Before relying on the result, check the current official guidance for the same tax year and jurisdiction. Distinguish enacted law from a consultation, draft measure, announcement or future proposal, and record the effective date. Reconcile the final estimate to the relevant return, payroll record or HMRC account. A calculator or explanatory guide can support a decision, but it cannot replace the eligibility test or the official filing and payment process.

Evidence and decision checks

A reliable uk iht100 new forms 2026 27 review starts by fixing the tax year and the date on which the relevant event happened. Record the person's or business's status, the income or transaction category, the amount before tax, tax already withheld, and any election or claim being relied on. Do not combine a headline figure with a final liability: the result can change when another income source, a payment date, an ownership interest or a qualifying condition is added.

Keep the source documents behind every important input. Depending on the subject, that may include payslips, invoices, bank statements, contracts, provider statements, travel records, HMRC notices, payroll submissions, valuations or correspondence. Where an amount is apportioned, write down the method and retain the underlying total. If a correction is made, preserve the original figure and explain the reason, date and evidence for the replacement.

Before relying on the result, check the current official guidance for the same tax year and jurisdiction. Distinguish enacted law from a consultation, draft measure, announcement or future proposal, and record the effective date. Reconcile the final estimate to the relevant return, payroll record or HMRC account. A calculator or explanatory guide can support a decision, but it cannot replace the eligibility test or the official filing and payment process.

For the wider trust reporting and ten-year-charge context, read the UK Inheritance Tax trust reporting guide and the UK trust tax guide. This page focuses on the post-31 August 2026 IHT100 form-version decision; it does not calculate an individual trust's Inheritance Tax liability.

Official sources

• HMRC Agent Update 144 — old IHT100 forms no longer accepted
• HMRC — Inheritance Tax account (IHT100) forms and guidance
• HMRC Inheritance Tax Manual — IHT100 suite introduction
• HMRC Inheritance Tax Manual — when to use IHT100 forms
• GOV.UK — tell HMRC that Inheritance Tax is due on a gift or trust