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Most technical founders leave tens of thousands of dollars unclaimed every year because they don't know their development work qualifies. This guide explains exactly what the credit is, who's eligible, and what documentation the IRS expects.
<30%
of eligible SMBs claim the credit
$5K–$30K+
cost of traditional R&D credit studies
3 years
you can look back with amended returns
6–8%
typical credit rate on qualifying wages
Understanding the credit
The federal R&D tax credit under IRC Section 41 provides a federal credit calculation based on qualified research expenses, subject to the taxpayer's method, base amount, limitations, elections, and filing facts. It was enacted in 1981 and made permanent in 2015.
Qualified research expenses (QREs) can include eligible wages for employees performing, directly supervising, or directly supporting qualified research and the permitted portion of qualifying contract-research costs. The Alternative Simplified Credit has different computations depending on prior-year QRE history; a flat percentage of wages is not the filed calculation in every case.
A US software business that paid $120K of W-2 wages for qualified services, with 70% supported as qualified activity, would have $84K of illustrative wage QREs before the credit method, base amount, limits, and elections are evaluated. Actual credit results require professional review.
Every activity must pass all four criteria defined in Form 6765 instructions to qualify:
The activity must intend to create or improve a product, process, or software in terms of function, performance, reliability, or quality.
There must be uncertainty about the capability, method, or design that could not be resolved by existing knowledge or standard practice.
The work must involve evaluating alternatives: through modeling, simulation, systematic trial and error, or other methods.
The activity must rely fundamentally on principles of engineering, computer science, or physical or biological sciences.
Eligibility
Entity type or a software-development label does not determine eligibility. The business must evaluate each activity under the four-part test and connect supported qualified services or contract research to amounts actually paid or incurred. Exclusions, domestic-research rules, credit methods, and the company's tax facts can change the result.
An owner-employee's actual W-2 wages may enter the review when the company can support qualified services. Owner draws, distributions, unpaid work, and future salary do not substitute for paid wages.
Actual wages for employees who perform, directly supervise, or directly support qualified research can be evaluated with the underlying activity evidence and applicable exclusions.
Tool use alone is not enough. Evidence should show the business component, technical uncertainty, alternatives considered, and a process of experimentation grounded in computer science or engineering.
A payroll-tax election may be available when the statutory gross-receipts and other requirements are met. A tax professional should evaluate the current limit, timing, aggregation, and filing mechanics.
The IRS recognizes three categories of qualifying employees: those directly performing qualified research, direct supervisors of qualified research, and direct support personnel. Marketing, sales, and general administration do not qualify.
Qualifying activities
The IRS software experimentation audit guidelines provides specific guidance on how software development qualifies. The key distinction: routine development does not qualify; experimentation does.
Building a new feature with unknown technical approach
Prototyping three different data pipeline architectures to find one that handles real-time classification at scale.
Evaluating AI model integration patterns
Testing multiple approaches for integrating LLM APIs: prompt engineering, fine-tuning, RAG, each evaluated for acceptable accuracy.
Resolving performance uncertainty
Systematic experimentation with caching strategies, database indexing, and query optimization to meet latency requirements.
Designing novel algorithms or data structures
Developing a custom deduplication engine to prevent double-counting across multiple data sources with overlapping timestamps.
Architectural experimentation
Evaluating serverless vs. container architectures, testing edge computing patterns, prototyping distributed system designs.
Routine bug fixes with known solutions
Fixing a typo in a CSS file. Updating a dependency version. Correcting a null pointer exception.
Deployment and DevOps execution
Running CI/CD pipelines, configuring DNS, deploying to production using established procedures.
Cosmetic UI changes
Changing colors, adjusting padding, swapping fonts. No technological uncertainty involved.
AI-assisted development is not automatically qualified research. It may support a candidate activity when the business can identify a technological uncertainty, alternatives evaluated through a process of experimentation, and the business component involved. The tool that produced code does not replace the four-part test or actual qualified-expense analysis.
Documentation
The IRS requires taxpayers to “retain records in a sufficiently usable form and detail to substantiate that the expenditures claimed are eligible for the credit.” In practice, this means you need contemporaneous records: documentation created at or near the time the work was performed, not reconstructed months later.
Records showing when R&D was performed, by whom, and on which project. Git commit histories, IDE heartbeat logs, and session timestamps all serve this purpose.
Project-level descriptions of the technological uncertainty addressed and the experimentation performed. Must reference the four-part test without revealing proprietary details.
Per-employee breakdowns showing how much time was spent on qualifying vs. non-qualifying work. The IRS accepts reasonable estimates supported by factual evidence.
Wages and other expenses tied to qualifying projects and activities. For wage-based credits, this means connecting employee time to specific R&D projects.
Git commits provide timestamped, author-attributed records of exactly when development occurred and on which projects: the definition of contemporaneous documentation.
Branch naming patterns and commit messages reveal experimentation: feature branches, prototype iterations, and A/B testing are visible in the commit graph.
IDE and AI coding tool plugins capture real-time R&D sessions (including time spent on architecture planning, uncertainty resolution, and alternative evaluation) that produce no commit artifacts.
Combined, these sources create a documentation trail that is generated automatically as you work, not reconstructed from memory months later.
Debunked
These shortcuts can obscure the activity, expense, and filing questions that control the result.
“You need to be doing lab science or hardware R&D.”
Software development can contain qualified research, but the label alone is not enough. Each activity still needs a permitted purpose, technological uncertainty, a qualifying process of experimentation, and a technological basis. Internal-use software can face additional rules.
“A company without income-tax liability has no research-credit path.”
A qualified small business may be able to elect a permitted amount against payroll taxes when the current gross-receipts, timing, aggregation, and filing requirements are met. The maximum election is not a guaranteed benefit.
“It's not worth it unless you have a large engineering team.”
Company size is not the test, but the economics still depend on actual qualified costs, the selected credit method, base amounts, limits, and filing facts. A rough wage percentage is only a starting illustration.
“The audit risk is too high for small companies.”
No documentation package eliminates examination risk. Contemporaneous records can help explain the business component, uncertainty, experimentation, people, costs, and calculation, but the taxpayer and advisor remain responsible for the filing position.
“Software can replace professional review.”
Software can organize records, estimates, and draft inputs. A qualified tax professional should still evaluate eligibility, elections, limitations, entity-specific treatment, and the filed return.
A better approach
A year-end review can depend heavily on memory when project, experimentation, people, and cost records were not connected near the time of the work. An ongoing evidence record can preserve useful context earlier, but every classification, allocation, and narrative still needs verification.
Reconstructed later
Ongoing evidence record
Contemporaneous records can help substantiate who performed the work, what uncertainty existed, which alternatives were evaluated, and how costs connect to the activity. They do not guarantee qualification or an examination result.
Working resource
Use the interactive checklist to organize business components, experiments, people, time allocations, expenses, exclusions, and current Form 6765 handoff questions. Progress measures evidence readiness, not eligibility.
Open the Software R&D Tax Credit Documentation ChecklistGo deeper
How the federal Section 41 research credit applies to software businesses, how it differs from Section 174A, and which facts and costs require review.
The IRS uses a four-part test to determine if business activities qualify for the R&D tax credit. Learn each criterion and how software development applies.
IRS Form 6765 is used to calculate and claim the R&D tax credit. Learn how to fill it out, which sections matter, and what documentation to keep.
Compare the Alternative Simplified Credit (ASC) and Regular Credit methods for calculating R&D tax credits. Learn which method produces a larger credit.
Software development can qualify for the R&D tax credit when it meets the statutory requirements. Learn how to assess the facts and exclusions.
Startups can use the R&D tax credit to offset payroll taxes even before they're profitable. Learn how the payroll tax offset works and how to claim it.
Learn which development records can support an R&D tax credit review and how to organize them with current Form 6765 requirements in mind.
Current federal treatment of domestic R&E expenditures under Section 174A, including deduction, amortization, transition, and foreign-research distinctions.
How Section 41 treats wages, supplies, computer-use costs, and contract research when calculating qualified research expenses for the federal credit.
An interactive, print-ready evidence checklist for software businesses preparing R&D tax credit records and Form 6765 support for CPA review.
Connect your code repository and QuarryFi runs a free current-year scan across your commit history, suggests activity review states, and shows an estimated credit range when the recorded facts support one.
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This content is for informational purposes only and does not constitute tax, legal, or accounting advice. QuarryFi is documentation preparation software, not a tax advisor. Consult a qualified CPA or tax attorney before claiming R&D tax credits. IRS guidance and regulations may change.