Reading ISO form numbers: CG, CP, CA and WC
Every commercial policy carries a schedule of forms — a list of coverage forms and endorsements by number and edition date. Learning to read those numbers is what turns a stack of pages into a comparison you can actually check. This is a guide to the FACTS of the numbering system; it does not reproduce any form's copyrighted wording.
The prefix tells you the line of business; the digits identify the specific form; the trailing date is the edition, and it matters as much as the number.
The line-of-business prefixes
Four prefixes cover most of commercial lines:
- CG — Commercial General Liability. The core form is CG 00 01 (the coverage form); CG 20-series numbers are additional-insured and related endorsements; CG 21-series are commonly exclusions.
- CP — Commercial Property. CP 00 10 is the building and personal property coverage form; the CP 10-series are causes-of-loss forms (special/broad/basic); CP 00 30 is business income.
- CA — Commercial Auto. CA 00 01 is the coverage form; the covered-auto symbols on the declarations decide what each coverage applies to.
- WC — Workers' Compensation. WC 00 00 00 is the standard policy; WC endorsements (and state-specific forms) modify it by jurisdiction.
Why the edition date is not optional
Two policies can carry the same form number with different edition dates and mean materially different things — ISO revises forms, and a revision can narrow or broaden coverage. That's why a proper renewal check compares number AND edition date, and treats an edition change as a flag to investigate, not a match.
Using the form schedule at renewal
The form schedule is the backbone of a renewal check: line the prior schedule up against the renewal schedule and any form added, removed or edition-changed jumps out. BindCheck does this diff automatically — comparing the two schedules by number and edition — and records only the form facts (number, edition, a short plain-English description), never the copyrighted form text.
Frequently asked questions
What does the edition date on a form mean?
It's the version of that form, printed as month/year (e.g. 04 13 = April 2013). Newer editions can change coverage, so at renewal an edition change on an otherwise-familiar form number is worth a closer look.
Are AAIS forms numbered the same way?
AAIS uses its own numbering, but the principle is identical: a prefix and number identify the form and an edition date identifies the version. A good check compares both regardless of the filing body.
Do you show the actual ISO form language?
No. ISO and AAIS form wording is copyrighted. We describe form facts only — number, edition and purpose — and compare those; the policy documents themselves remain your source for the exact language.
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