What Documentation Does the IRS Expect for R&D Tax Credit Claims?

In brief

• The law requires records that substantiate the credit; it does not prescribe a particular format.
• The IRS expects to see both what research was done on each business component and what it cost, and the connection between the two.
• Engineering records such as commits, tickets and chat messages help show what happened. They do not, on their own, prove that research was qualified research.

The recordkeeping rule

The same regulation adds that the IRS and taxpayers “may agree to guidelines for the keeping of specific records”. Outside such an agreement, the regulation sets a standard (usable, detailed, substantiating) rather than a list of documents.

Records that support the research activities

Under §41(d) and Treas. Reg. §1.41-4, the activity records need to support, for each business component, the four tests: permitted purpose, technological in nature, elimination of uncertainty and process of experimentation. Useful records include:

• Technical project descriptions: what the component is and what was to be new or improved (function, performance, reliability or quality).
• Business-component identification: names or identifiers used consistently in engineering, finance and on Form 6765.
• Technological uncertainties: what the information available at the start did not establish (capability, method or appropriate design).
• Experimentation records: hypotheses, test plans, simulations, benchmarks and their results.
• Failed approaches and iterations: what was tried and abandoned, and why.

Engineering tools: useful, not sufficient

Tickets, source-control history, build results and team chat can show who changed what, when, and in what order, and can corroborate an account of experimentation: an approach implemented, a test that failed, a change, a test that passed.

Records that support the expenses

Wages

Wage QREs are wages for “qualified services”: engaging in, directly supervising or directly supporting qualified research (Treas. Reg. §1.41-2). Where an employee did both qualified and other work, only the wages allocated to qualified services count. In the absence of a more appropriate method the taxpayer can demonstrate, the regulation allocates by the ratio of time actually spent on qualified services. Personnel records therefore need to show who did what kind of work, on which component, and for how long.

Contractors

Contract research expenses are generally included at 65% of the amount paid (with higher percentages for some research organisations); keep the agreements, invoices and evidence of what the contractor did and on which component.

Supplies and computer use

Supplies count where used in the conduct of qualified research; computer rental counts only for computers off the taxpayer’s premises that the taxpayer does not operate and is not the primary user of (Form 6765 instructions, column 55). Keep invoices and evidence of use by component.

Connecting activities to expenses

The IRS’s Research Credit Claims Audit Techniques Guide (revision May 2008) calls this the “nexus”: “the inability to connect specific research project(s) and the underlying activities to the qualified expenses” is, in its words, “the nexus problem”. It notes that project-based accounting “generally establishes the required nexus”, whereas cost-centre accounting does not always, and that “arbitrary and unsupported allocations should not be accepted”.

Retention and retrieval

Treas. Reg. §1.6001-1(e) requires records to be kept available for inspection and retained “so long as the contents thereof may become material in the administration of any internal revenue law”. For the research credit that can be a long time: base-period computations and carryforwards can make older records material again.

Retrieval matters as much as retention. Records spread across tools that are later replaced, repositories that are archived and accounts belonging to staff who have left are hard to produce when asked.

The limits of retrospective documentation

The RCCATG tells examiners that information supporting a claim “should be contemporaneous and available for inspection”, to consider how much time passed between the research and any oral testimony, and that “the Service does not have to accept either estimates or extrapolations”. Reconstruction after the event, from interviews and memory, is therefore weaker evidence, especially where the people who did the work have moved on.

Requirements versus recommended practice

Professional workflow implications

• Set up business components and their identifiers with the client at the start of the year.
• Agree how time will be recorded by component, including supervision and support.
• Collect technical records during the year, grouped by component, with their source references.
• Write the four-part analysis per component and cite the records it relies on.
• Keep the professional judgement separate from the records: the records are facts, the analysis is the professional’s.

Evidence checklist

A practical list for organising records. It is a recordkeeping aid, not a test of whether work qualifies.

• A technical description of each business component and what the research set out to do.
• The technological uncertainty at the start, and why existing information did not resolve it.
• The alternatives considered and how each was evaluated (tests, simulations, prototypes, benchmarks).
• Failed approaches and iterations, with dates.
• Engineering records (tickets, source control, build results) grouped by component and kept with their references.
• Who performed, directly supervised or directly supported the research, and for how much of their time.
• Payroll records reconciling to the wage QREs; supply invoices; contract research agreements and invoices.
• The method used for any allocation or sampling, written down, and the professional’s analysis per component.

Where Evidante fits

Official sources

Grouped by what kind of source each is, because they do not carry the same weight. Checked on 11 Oct 2026.

Educational information only. Not tax or legal advice. This guide concerns the federal research credit; state credits have their own rules. Rules change and depend on the taxpayer and tax year; check the current IRS sources and take professional advice before acting. Evidante is not endorsed by the IRS.