Short answer. For almost every modern company, the alternative simplified credit (ASC) wins: it needs only the last three years of data, while the regular credit needs 1984 to 1988 base-period records most firms cannot reconstruct. Use the regular method only with clean 1980s records and a low fixed-base percentage.

The two methods side by side

Same credit, two formulas, very different record requirements.

FactorRegular creditAlternative simplified credit
RateUp to 20% of qualified research above a base amount14% above 50% of the average of the prior three years
Data requiredA fixed-base percentage tied to gross receipts and research from 1984 to 1988Only the last three years
Practical fitCan be larger, but the base-period data is often impossible to reconstructLower headline rate, but usable by almost any modern company
Winner / best forCompanies with clean 1980s records and a low fixed-base percentageAlmost every modern company

Which one wins

It turns on history and records, not on the headline rate.

The regular credit can beat ASC for a company with a low fixed-base percentage and clean records back to the 1980s. Few modern companies have either, which is why ASC dominates in practice.

A company can compute both and elect the better result, subject to the rules on when the ASC election can be made and changed. That is a return decision for the CPA.

What both methods need

The method changes the formula, not the substantiation.

Either way, the credit rests on the same qualified research expenses, supported by the same four-part-test evidence per business component. The method is arithmetic on top of that foundation.

R&D Binder builds that foundation so either calculation has defensible inputs.

Sources

Every claim on this page traces to a primary authority. Each source below is independent and verifiable.

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R&D Binder produces the qualified-research-expense figures both methods run on, so your CPA can compute either and choose. The binder is the evidence; the method election is theirs.