Substantiation is the whole game on credits and elections. The computation is rarely the hard part. Reproducing it on demand, a year later, with the assumptions visible, is.
books and records should form the basis of any examination. Estimation is allowed only where records are absent through no negligence of the taxpayer. IRS Audit Techniques Guide, IRC 41
assumption underlying an estimate needs factual support. The burden of proof sits with the taxpayer. IRS Audit Techniques Guide, IRC 41
comparative analysis of qualified research expenses is an initial step examiners use to identify compliance risk. IRS Audit Techniques Guide, IRC 41
expenses and gross receipts must be aggregated with one credit computed and allocated. A common and expensive omission. IRS Audit Techniques Guide, IRC 41
A spreadsheet answer and a defensible answer are different artifacts. The second names the statute it applied, shows the intermediate figures, and produces the same result when someone re-runs it in front of an examiner.
Six that close the biggest gaps. 26 in the full finance, tax and accounting library.
The gap it closes. Regular versus alternative simplified credit, the base-period computation, and controlled-group aggregation are where the credit is either supported or lost. Each intermediate figure is shown rather than folded into a total.
See it run in your browser →The gap it closes. The wage and UBIA limitations phase in over a threshold range and the specified-service rules can zero the deduction entirely. The binding constraint should be visible, not inferred from one output number.
See it run in your browser →The gap it closes. Convention, recovery period and method determine the schedule, and a mid-quarter convention triggered by fourth-quarter placements changes every year of it.
See it run in your browser →The gap it closes. A first-digit distribution test is the standard screen for fabricated or manipulated figures, and it works on data you already hold without asking anyone what they did.
See it run in your browser →The gap it closes. Economic nexus thresholds differ by state in both dollar amount and transaction count, and crossing one creates a filing obligation that predates anyone noticing.
See it run in your browser →The gap it closes. IRR is a root-finding problem that can have multiple solutions or none on irregular cash flows. A single returned number hides which case you are in.
See it run in your browser →Not tax, accounting, audit or investment advice, and no substitute for a CPA or tax counsel. Rates, thresholds and limits are dated inputs you confirm for the applicable year, and the tool reports which ones it used so a prior-year figure cannot silently produce a current-year answer.
Every tool above runs entirely in this browser tab. Nothing is uploaded, nothing is sent to a model, and each result cites the rule it applied.
Free tier, no card, no install. An account saves your work and lets you export a citable record of a run. See all 26 finance, tax and accounting tools.