How to Make a Claim

The Additional Information Form (AIF)

Every R&D claim now needs an Additional Information Form, submitted before or with the return. It is where the projects, the costs, the responsible officer and every agent involved go on the record. File the return first and the claim is rejected; write the form thinly and you have drafted HMRC's first enquiry letter yourself.

Written and reviewed by the InnoClaim team, a firm of Chartered Tax Advisers. Last reviewed 8 July 2026.

What the form is for

The Additional Information Form is HMRC’s screening instrument. Before it existed, an R&D claim could arrive as little more than numbers in a return. Now the substance arrives structured: company details, the accounting period, qualifying expenditure broken into its categories, project descriptions, the senior internal contact responsible for the claim, and the details of any agents involved.

HMRC’s guidance states the two hard mechanics plainly. You must complete and submit the form to support the claim, with one form for each accounting period. If you do not, or if the return is filed first, the claim will not be accepted or will be rejected.

The parts that carry risk

The project descriptions. Each described project must show the advance sought, the uncertainties, why they were not readily resolvable by a competent professional, and how the work addressed them. This is the same statutory test as everywhere else, compressed into a form field, and it is where thin claims become visible. How to write them properly has its own page: the technical narrative.

The cost breakdown. The categories mirror the statutory ones, staff, EPWs, contractors, consumables, software, data and cloud, and the numbers here must reconcile to the return and survive the apportionment questions on qualifying costs.

The named officer. The form asks for the main senior internal contact responsible for the R&D claim, for example a company director. Treat the field as what it is: the person who stands behind the claim when HMRC calls.

The agents. Details of all agents involved in the claim go on the form, whoever advised, analysed costs, drafted narratives or filed. For companies, this is protection: the market’s anonymous operators are gone. For advisers, it is accountability by design.

Sequencing, in one line each

  1. Claim notification first, if you are within the notification rule.
  2. AIF submitted before or with the return.
  3. Return filed with the R&D figures, and the box ticked confirming the AIF has been submitted.

The return-side entries and boxes are covered in how to make a claim.

Sources
  1. HMRC, Additional information you must submit before you claim R&D tax relief, gov.uk
  2. HMRC, Make a claim for R&D tax relief on your Company Tax Return, gov.uk

Frequently asked questions

Is the AIF really mandatory for every claim?

Yes. HMRC's guidance is explicit: without it, the R&D claim will not be accepted, and one form is needed for each accounting period claimed. It applies to the merged scheme, ERIS, and claims under the old schemes alike.

What happens if the tax return goes in first?

HMRC states that if the return is submitted before the Additional Information Form, the claim will be rejected. The fix is sequencing, not argument: AIF first, then the return, with the box ticked to say the form has gone in.

Who should the named contact be?

The form asks for the main senior internal contact responsible for the claim, for example a company director. It should be someone who genuinely stands behind the claim, because that is what the role means, and enquiries will start with them.

Do we have to name our adviser?

Yes. Details of every agent involved in the claim go on the form, advisory or preparatory. Anonymous involvement in R&D claims no longer exists, which is one of the reforms doing the most quiet work in this market.

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