ICC-ES Acceptance Criteria
What an AC number means, and what only an evaluation report can tell you
Last updated: September 14, 2026
Overview
An ICC Evaluation Service Acceptance Criteria document, written as AC followed by a number, sets out how a category of building product gets evaluated. It defines the test methods, the performance thresholds, and the quality control a manufacturer has to satisfy. It is the yardstick.
What it is not is evidence about any particular product. An AC number on its own does not show that a product was ever submitted, tested, evaluated, or recognized. The document that does that is an ICC-ES Evaluation Report, written as ESR followed by a number, and it names the specific products it covers along with the conditions they were evaluated under.
If a product listing cites only an AC number, it has told you which rulebook applies to that product category. It has not told you the product was measured against it. Ask for the ESR number.
AC or ESR: which document answers your question
| Question | Document that answers it |
|---|---|
| How is this category of product tested? | The Acceptance Criteria (AC) |
| Was this specific product evaluated, and what does it cover? | The Evaluation Report (ESR) |
| Which code editions does the evaluation address? | The ESR, in its Evaluation Scope section |
| What has to be true on site for the evaluation to apply? | The ESR, in its Conditions of Use section |
| Will the building official accept it? | The authority having jurisdiction. ICC-ES reports are advisory and state that they are not an endorsement. |
Criteria we cover
We write about a criterion only where we stock products whose evaluation report cites it, so the page can point at real evidence rather than restate a rulebook.
Checking what a product actually holds
- Get the ESR number from the manufacturer, not the AC number.
- Look the report up in the ICC-ES Reports Directory and confirm it is current. Reports carry a reissue date and a renewal date, and ICC-ES can revoke one between them.
- Find your exact product in the report. A report covers named products, and a component named inside a system report is not the same as a product with its own report.
- Read the Conditions of Use. These routinely include installation requirements, and a system built outside them is outside what the report evaluated.
- Check the code editions in the Evaluation Scope against the edition your jurisdiction has adopted.
Frequently Asked Questions
Is a product "AC compliant"?
That phrasing does not really work on its own. ICC-ES describes products as evaluated to the requirements of a criterion, with the resulting evaluation report as the evidence of code compliance. Compliance is stated against code provisions, and the ESR is what connects a product to them.
What is the difference between an AC number and an ESR number?
The AC is the criteria a category of product is evaluated against. The ESR is the report issued for specific products that were evaluated. Every ESR names the criteria it used in its Evidence Submitted section, which is why the two numbers often appear together.
Does ICC-ES approve products?
No. ICC-ES evaluates products and issues reports. Its reports state that they are not an endorsement of the product and not a recommendation for its use, and the final acceptance decision belongs to the authority having jurisdiction.
Why do some AC numbers now have a year in brackets?
In April 2025 ICC-ES changed its numbering so an AC number carries the newest referenced code edition in parentheses, such as AC271 (24), followed by alphabetic revision tracking. The suffix marks the edition. It does not mean the number was reassigned to a different subject.
A supplier says a part is an "evaluated component." Is that meaningful?
Only if they can name the report. A component can appear inside a system report without holding a report of its own, which is a narrower claim than it sounds: what was evaluated is the assembly, built as the report describes. Ask which ESR names the part, and which system in it.