R&D tax credit evidence · checked against the sources on

R&D tax credit documentation requirements

The regulation asks for records in sufficiently usable form and detail to show that each expense claimed is eligible (Treas. Reg. §1.41-4(d)). In George v. Commissioner, T.C. Memo. 2026-10, the Tax Court rejected credit studies reconstructed after the fact. For a software team, the records are the commits, pull requests, design notes and test results made at the time, tied to each business component, and the payroll records that show who was paid for the work. A narrative written in March about last year summarises those records; it does not replace them.

“must be grounded in records created during the course of the work itself”

PKF O'Connor Davies: George v. Commissioner, T.C. Memo. 2026-10 (published 9 Mar 2026; read 9 Oct 2026)

Evidence to review with your tax adviser; not tax advice.

What counts as a record

What the court said in 2026

In George v. Commissioner (T.C. Memo. 2026-10), a poultry producer claimed the credit for feed, vaccine and genetics trials. The court took each initiative separately through the four-part test, and rejected credit studies prepared later to reconstruct the work. A summary of the case: PKF O'Connor Davies.

What a software team's history supplies

The commits, with their dates, authors and messages, and the pull requests around them, are records made during the work. They show alternatives tried (reverts, branches never merged, pull requests closed), and the words people wrote about prototypes and benchmarks. They do not show hours, wages, or the uncertainty nobody wrote down. Strike Tax makes the same case for git, and the same warning about vague messages.

Keep it as you go

A file written each month, from that month's history, and kept with your tax records the same day, shows that it existed then. The same index assembled next March is a summary written after the fact, however accurate. The steps below take a few minutes on the 1st of each month.

If you claim in the UK

HMRC's Additional Information Form asks, for each project, what existing knowledge it set out to improve, the advance it sought, the uncertainties it faced, and how it tried to overcome them, with the costs by category. Everything has to be in the form itself: HMRC does not accept a reference to documents held elsewhere (CIRD182000). The same history is where those answers come from.

Check your own, on your machine

npx --allow-git=root github:agentwares/rd-ledger --month previous
  1. On the 1st of each month, fetch every branch: git fetch --all
  2. Write last month's commits to a dated file: git log --all --since=2026-09-01 --until=2026-10-01 --date=short --format='%ad,%h,%an,%s' > rd-2026-09.csv
  3. Write down the branches not merged into main, the approaches still open or abandoned: git branch -a --no-merged main > rd-2026-09-branches.txt
  4. Keep the file with your tax records the same day, so it shows it existed then; one written next March would not.
  5. Ask the engineers to say what they tried and why in their commit messages: "updates" and "wip" leave nothing to cite.

It runs git on your repository, makes no network request and calls no LLM, and writes a dated evidence pack, evidence.md and CSVs, with each line traced to its commit. Hours and amounts appear only from figures you supply. Source (MIT)

A year-round R&D evidence ledger, kept month by month as the work happens, is not built. Each month's evidence captured that month and kept under a date we hold, so the record shows when it existed; at year end, the hours or wages you enter allocated across your business components in Form 6765 Section G's shape; and a read-only link for your tax adviser.

Not built. No price is set and nothing is charged. It gets built only if enough people ask.

Count me in

Sources

Other R&D credit questions