The R&D tax credit is one of the most defensible incentives in the tax code—when properly documented. "Properly" is the operative word. Credits that survive audits are built on contemporaneous documentation that supports each element of the four-part test. Credits that get disallowed typically fail on documentation, not on the underlying activity.
The Four Documentation Requirements
For each qualified research activity, you need documentation establishing: (1) the activity had a permitted purpose—developing or improving a business component, (2) the research was technological in nature—using principles of hard science, (3) there was technical uncertainty about capability, method, or design, and (4) there was a process of experimentation—systematic evaluation of alternatives.
Project-Level Documentation
Beginning with 2026 tax years, Form 6765 Section G requires project-level detail for most filers. This means documenting each research project separately with information about the business component being developed, the technical uncertainty, the experimentation process, and the qualified expenses associated with each project. Start building this infrastructure now if you have not already.
Wage Documentation
Qualified wages are the largest category of qualified research expenses for most companies. For each employee whose wages are included, you need documentation of the percentage of their time spent on qualified research activities. Time-tracking records, project allocation systems, or retrospective surveys with contemporaneous corroboration are all acceptable methods—but the documentation must exist.
Key Takeaways
- Documentation is where most R&D credits fail—not the underlying activity.
- Form 6765 Section G (effective 2026) requires project-level detail for most filers.
- Wage allocations need supporting documentation for each employee whose time is claimed.
