What evidence and documentation is required for ERIS?

An ERIS claim should be supported by records that demonstrate both that the underlying activities qualify as R&D and that the expenditure included in the claim has been calculated accurately. HMRC does not require companies to maintain a specific set of documents solely for R&D tax relief, but businesses are expected to retain sufficient records to support the figures included in their Corporation Tax return. The evidence should allow the company to explain how it identified qualifying projects, how those projects met the R&D criteria and how the associated costs were calculated.

The evidence available will vary between businesses and projects. HMRC recognises that smaller companies may not have formal R&D systems or extensive project documentation. Existing business records can often provide useful evidence, provided they allow the company to demonstrate what work was undertaken and why it qualifies. HMRC recommends that records are proportionate to the size and complexity of the project rather than creating unnecessary documentation simply for the purpose of making a claim.

HMRC may expect the following supporting evidence to be available:

Project documentation:

Planning documents, project descriptions, technical specifications and other records showing what the project was intended to achieve and the work undertaken.

Technical evidence:

Documents demonstrating the scientific or technological advance being sought and the uncertainties that needed to be resolved. This could include technical reports, design documents, test results, research notes, development records and records of failed or successful testing.

Contemporaneous records:

Emails, meeting notes, project updates, development logs, drawings, photographs of prototypes and other records created during the project can help demonstrate that the R&D activity actually took place. Evidence created during the project is particularly useful because it can provide a contemporaneous record of the uncertainties encountered and the steps taken to resolve them.

Staff records:

Payroll information, employment records, timesheets, project tracking systems or other evidence showing which employees worked on the R&D and the proportion of their time attributable to qualifying activities.

Expenditure records:

General ledger information, invoices, purchase records, payroll records and other accounting documentation supporting the qualifying expenditure included in the claim. HMRC may use these records when checking whether the expenditure claimed is accurate and relates to the qualifying R&D activity.

Cost allocation records:

Where employees, software, consumables or other resources are used across both R&D and non-R&D activities, the business should retain evidence showing how the relevant costs have been apportioned. The methodology should be reasonable, consistent and capable of being explained if HMRC asks how the figures were calculated.

Accounting and tax records:

The R&D calculation should reconcile to the company’s accounting records and Corporation Tax computation. The company should be able to demonstrate how the qualifying expenditure feeds into the ERIS calculation and ultimately into the tax return.

Additional Information Form (AIF):

An AIF must be submitted to HMRC to support an ERIS claim. The form provides details of the company, the accounting period, the R&D expenditure claimed and the projects undertaken. It must be submitted before or on the same day as the R&D claim is made. If the required information is not provided, the R&D claim is invalid.

Technical project descriptions:

The AIF requires information about the R&D projects, including the field of science or technology, the advance being sought, the scientific or technological uncertainties encountered and how the project attempted to resolve those uncertainties. HMRC expects

these descriptions to be supported by the company’s underlying records rather than being prepared as an isolated narrative after the event.

Claim Notification Form (CNF):

Where the company is required to notify HMRC of its intention to make an R&D claim, the relevant claim notification must also be completed within the applicable deadline. The notification process is separate from the evidence supporting the actual ERIS calculation and should not be treated as a substitute for maintaining underlying project and financial records.

Good ERIS documentation should therefore tell a consistent story from the original R&D activity through to the final tax calculation. The technical records should demonstrate why the work qualifies, while the financial records should demonstrate how the qualifying expenditure was identified and calculated. These records should also be consistent with the information provided on the AIF and the figures submitted in the Corporation Tax return.

The purpose of maintaining this evidence is not to create eligibility where none exists. Instead, it gives the company a defensible evidence base if HMRC reviews the claim. Where HMRC opens a compliance check, it may request relevant documents, examine project records, review expenditure and speak to employees involved in the work.