Written by Acorn Sales Company, manufacturing stamps and seals since 1964 · Reviewed by Holly R, VP of Sales and Marketing at Acorn Sales, against the State Board of Licensure for Architects, Professional Engineers, and Professional Land Surveyors and C.R.S. §§ 12-120-216(1) and (2), 12-120-316(2) on 21 September 2026 · Updated 21 September 2026
Colorado requires the signature and date to appear through the seal, not beside it. Rule 1.5(A)(3) says exactly that, and rule 1.6(A)(3) repeats it for land surveyors. That one sentence settles the device question: the statute authorizes a crimp type seal and a licensee may own one, but an embossed impression on a reproducible gives a signature nothing to cross.
The geometry is two circles, and both are specified: outer nominally 1-5/8 inches (41 mm), inner nominally 15/16 inches (24 mm). The upper arc reads COLORADO LICENSED and the lower arc reads PROFESSIONAL ENGINEER, with the license number centered in the inner circle. A single-ring die does not match the approved design.
One trap catches buyers who forward the board’s artwork to a supplier as it stands. That artwork carries the placeholder word NUMBER inside the inner circle, and rule 1.5(A)(1) says the assigned license number goes in that space at the same letter size and that the word NUMBER should not appear on the seal.
Colorado PE seal requirements at a glance
| Requirement | Colorado rule | Source |
|---|---|---|
| Seal required | Yes | C.R.S. §§ 12-120-216(1) and (2), 12-120-316(2) |
| Required elements | Your name, Your license number, centered in the inner circle, The arc legend “COLORADO LICENSED” and The arc designation “PROFESSIONAL ENGINEER” | C.R.S. § 12-120-216(1) |
| Size and shape | Outer circle nominally 1-5/8 inches (41 mm); inner circle nominally 15/16 inches (24 mm). | 4 CCR 730-1, Rules 1.5(A)(1), 1.6(A)(1) and 1.7(A)(1) |
| Device allowed | Three devices are authorized by name in both the statute and the rule: “the seal authorized by the State Board of Licensure for Architects, Professional Engineers and Professional Land Surveyors for licensees is of the crimp type, rubber stamp type, and/or computer generated type.” Crimp means an embosser. | C.R.S. § 12-120-216(1) |
| Signature and date | Rule 1.5(A)(3): “The manual or electronic signature of the licensee and date of signature shall be affixed to the document. | 4 CCR 730-1, Rules 1.5(A)(3), 1.6(A)(3) and 1.7(A)(1) |
| What must be sealed | For engineers: each sheet of engineering drawings, the cover or title or table of contents pages of specifications bound in book form, the title pages of details bound in book form and prepared to supplement project drawings, and the title or signature page of engineering reports. | 4 CCR 730-1, Rules 1.5(A)(2), (4), (5), (6) and (7) |
| Electronic seal | Colorado names two technologies. | 4 CCR 730-1, Rule 1.2(B) |
| Renewal and lapse | All architect, professional engineer and professional land surveyor licenses expire on October 31 of odd-numbered years, so Colorado is a statewide two-year cycle. | 4 CCR 730-1, Rules 1.3(A)(3) and 1.4(I)(1) |
| Firm number on documents | Not applicable. | C.R.S. § 12-120-216(2) |
| Licensing board | The State Board of Licensure for Architects, Professional Engineers, and Professional Land Surveyors | 4 CCR 730-1, Architects, Professional Engineers, |
Rules for other states are on PE stamp requirements by state.
Is a seal required in Colorado?
Colorado requires a seal The statute is permissive about owning a seal and the board rule is mandatory about using one. C.R.S. 12-120-216(1) says a professional engineer “may obtain a crimp type seal, a rubber stamp type seal, or an electronic type seal of a design approved by the board”, and subsection (2) limits use to work prepared under the engineer’s responsible charge. The obligation to apply it comes from the board: Rule 1.5(A)(2), “A manual or electronic seal must be applied to either the final reproducible, the final reproduction, the final electronic record document, or record set” of each sheet of engineering drawings, the cover or title or contents pages of bound specifications, the title pages of bound details, and the title or signature page of engineering reports. For land surveyors the mandate is also statutory: C.R.S. 12-120-316(2) requires all documents, plats and reports resulting from the practice of land surveying to bear the seal, signature and date.
What must appear on the seal
- Your name
- Your license number, centered in the inner circle
- The arc legend “COLORADO LICENSED”
- The arc designation “PROFESSIONAL ENGINEER”
The board’s artwork uses the placeholder word NUMBER inside the inner circle, and the rule is explicit that the placeholder must not survive into the finished device: “The license number assigned shall be centered in the inner area of the seal in the space occupied by the word ‘NUMBER’ and the size of the numbers shall be the same size of the letters in the word ‘NUMBER’. The word ‘NUMBER’ should not appear on the seal.” Colorado also publishes a combined design for dual licensees whose lower arc reads “P.E. AND P.L.S.” rather than the single profession. There is a grandfather clause, and the statute and the rule give different dates for it: C.R.S. 12-120-216(1) protects seals held by engineers licensed before July 1, 2004, while Rule 1.5(A)(1) says “Seals obtained prior to July 1, 2005 shall be deemed acceptable.” The same split appears on the architect side, where the statute says licensed before July 1, 2013 and Rule 1.7(A)(1) says seals obtained prior to September 1, 2015.
Size and shape
Outer circle nominally 1-5/8 inches (41 mm); inner circle nominally 15/16 inches (24 mm). Rule 1.5(A)(1) states both figures for professional engineers, and Rules 1.6(A)(1) and 1.7(A)(1) repeat the identical dimensions word for word for professional land surveyors and architects. The word is nominally, so the rule tolerates ordinary manufacturing variation, but the two-circle geometry with a specified inner diameter is unusual and a single-ring die does not match the approved design.
Embosser, rubber stamp or digital
Three devices are authorized by name in both the statute and the rule: “the seal authorized by the State Board of Licensure for Architects, Professional Engineers and Professional Land Surveyors for licensees is of the crimp type, rubber stamp type, and/or computer generated type.” Crimp means an embosser. All three are equally legal, and the rule uses and/or, so a licensee may hold more than one. The safe buy is the rubber stamp, because the signature has to run through the seal and an embossed impression gives nothing to sign through on a reproduction.
Signing and dating
Rule 1.5(A)(3): “The manual or electronic signature of the licensee and date of signature shall be affixed to the document. The signature of the licensee and date of signature shall appear through the seal.” Through the seal, not beside it. The date is the date of signature. Architects are governed by a parallel but differently worded rule: Rule 1.7(A)(1) requires “the original signature of the individual named on the seal and the date of the signature” to appear “across the face of each original seal imprint”, with an exception allowed only as required for compliance with a federal contract. Land surveyors use the engineer wording: signature and date through the seal.
The signature runs through the seal, so the device has to be an inked stamp
Colorado does not put the signature next to the seal. Rule 1.5(A)(3) requires that “the signature of the licensee and date of signature shall appear through the seal”, and the land surveyor rule at 1.6(A)(3) says the same. The architect rule says it differently and even more plainly: the original signature and the date must appear “across the face of each original seal imprint”.
That single sentence settles the device question. The statute authorizes a crimp type seal, and a licensee may own one, but an embossed impression on a reproducible gives the signature nothing to cross. The practical Colorado purchase is a rubber stamp with an open center, sized so a signature and a date fit across the inner circle without burying the license number.
The second Colorado-specific trap is the placeholder. The board’s approved artwork carries the word NUMBER in the inner circle, and buyers routinely send that artwork to a supplier as-is. The rule anticipates exactly that mistake and forbids it: the assigned license number goes in the space the word NUMBER occupies, at the same letter size, and “the word ‘NUMBER’ should not appear on the seal.” There is also a distinct approved design for dual licensees, whose lower arc reads P.E. AND P.L.S. instead of naming one profession.
Which documents must be sealed
For engineers: each sheet of engineering drawings, the cover or title or table of contents pages of specifications bound in book form, the title pages of details bound in book form and prepared to supplement project drawings, and the title or signature page of engineering reports. A cover-page-only alternative exists for electronic seals if the cover carries the identical sheet border, title block and project title, every page is numbered, every title block notes that the seals are on the cover, and the seal carries a statement of the scope of work. Preliminary work is not exempt but must be labeled: “When a licensee seals engineering documents that are not final, the status of the engineering documents must be identified as preliminary.” A licensee who signs and seals is responsible for the entire document unless a written note adjacent to the seal limits the scope to named disciplines. Manufactured components that are statutorily exempt may be specified without the licensee taking responsibility for their internal design. Sealed documents must be retained for at least the statute of repose under C.R.S. 13-80-104.
Electronic and digital seals
Colorado names two technologies. Rule 1.2(B): an electronic signature “can be generated by using either public key infrastructure or signature dynamics technology” and must be unique to the person using it, capable of verification, under that person’s sole control, and linked to the document so that the signature is invalidated if any data in the document are changed. The rule defines PKI as a technology in which trusted parties digitally sign documents certifying that a cryptographic key belongs to a particular user or device, and Signature Dynamics Technology as a commercial eSignature application dedicated to secure routing, authentication and verification with an audit trail. One requirement is technology-specific rather than criteria-based: when a licensee electronically seals only the cover page of a set of drawings, “Signature Dynamic Technology shall be used.”
Renewal, lapse and retirement
All architect, professional engineer and professional land surveyor licenses expire on October 31 of odd-numbered years, so Colorado is a statewide two-year cycle. The license number does not change on renewal or on reinstatement of an expired or retired license, so the seal does not have to be recut. An expired or retired license may be reinstated by application and fee within two years; a professional land surveyor whose license has been expired more than six years must retake the Colorado state specific surveying examination. Rule 1.3(A)(3) places the custody duty on the licensee: “Licensees shall be personally and professionally responsible and accountable for the care, custody, control, and use of their seals.” For land surveyors the same rule extends to unused monument caps bearing the license number. Nothing requires the seal to be surrendered or destroyed.
Firm registration
Not applicable. Colorado does not license or register engineering, surveying or architecture firms and issues no certificate of authorization. C.R.S. Title 12 Article 120 runs Part 1 general provisions, Part 2 Engineers ending at 12-120-216, Part 3 Land Surveyors and Part 4 Architects, and contains no firm registration provision; the Division of Professions and Occupations publishes applications only for individual architects, engineers, land surveyors and their intern credentials. No firm number appears on Colorado sealed documents and no firm holds a seal. Responsibility is attached to the individual through the responsible charge test in C.R.S. 12-120-216(2) and the scope-limiting note in Rule 1.5(A)(5).
What to check before you order
Your seal is two concentric circles, the outer nominally 1-5/8 inches (41 mm) and the inner nominally 15/16 inches (24 mm). COLORADO LICENSED runs along the upper arc with your name beneath it, your license number sits centered in the inner circle at the same size as the surrounding lettering, and the lower arc reads PROFESSIONAL ENGINEER, PROFESSIONAL LAND SURVEYOR, ARCHITECT, or P.E. AND P.L.S. if you hold dual licensure. The word NUMBER must never be left on the die. Take the rubber stamp, because Colorado requires your signature and date to cross the seal face, and keep the inner area clear enough to sign through. Colorado imposes no proof-of-licensure requirement before your seal is made, and a seal obtained before the grandfather dates stays usable, so there is no compliance reason to replace one you have held for years.
Browse professional engineer stamps and seals.
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Frequently asked questions
Is a PE seal required in Colorado?
Yes, by board rule. C.R.S. 12-120-216(1) is permissive about owning a seal, saying an engineer may obtain a crimp type, rubber stamp type or electronic type seal of a design approved by the board. The obligation to apply it comes from Rule 1.5(A)(2), which requires a manual or electronic seal on the final reproducible, final reproduction, final electronic record document or record set. For land surveyors the mandate is statutory as well: C.R.S. 12-120-316(2) requires all documents, plats and reports resulting from land surveying to bear the seal, signature and date.
What size is a Colorado PE seal?
Outer circle nominally 1-5/8 inches (41 mm) and inner circle nominally 15/16 inches (24 mm), under Rule 1.5(A)(1). Rules 1.6(A)(1) and 1.7(A)(1) give the identical figures for land surveyors and architects. The word is nominally, so ordinary manufacturing variation is tolerated, but the two-circle geometry with a specified inner diameter is not optional.
What wording goes on a Colorado PE seal?
Your name, your license number centered in the inner circle, the arc legend COLORADO LICENSED, and the arc designation PROFESSIONAL ENGINEER. A licensee holding both credentials uses the board’s combined design, whose lower arc reads P.E. AND P.L.S. rather than naming one profession.
Should the word NUMBER appear on my Colorado seal?
No. It is a placeholder in the board’s published artwork. Rule 1.5(A)(1) requires the assigned license number to be centered in the inner area in the space the word NUMBER occupies, at the same size as the letters in that word, and states that the word NUMBER should not appear on the seal.
Embosser or rubber stamp in Colorado?
Both are authorized, along with a computer generated seal, by name in the statute and the rule. The practical buy is the rubber stamp, because Rule 1.5(A)(3) requires the signature and date to appear through the seal and an embossed impression offers nothing to sign across. Leave the inner area open enough that a signature and a date fit without burying the license number.
Which documents must be sealed in Colorado?
Each sheet of engineering drawings; the cover, title or table of contents pages of specifications bound in book form; the title pages of details bound in book form to supplement project drawings; and the title or signature page of engineering reports. A cover-page-only alternative exists for electronic seals, but only if the cover carries the identical sheet border, title block and project title, every page is numbered, every title block notes that the seals are on the cover, and the seal carries a statement of the scope of work.
Do I have to label preliminary work in Colorado?
Yes. Preliminary work is not exempt from sealing, but Rule 1.5(A)(5) requires that when a licensee seals engineering documents that are not final, the status must be identified as preliminary. A licensee who signs and seals is responsible for the entire document unless a written note adjacent to the seal limits the scope to named disciplines. Sealed documents must be retained for at least the statute of repose under C.R.S. 13-80-104.
What electronic signature technology does Colorado accept?
Rule 1.2(B) names two: public key infrastructure and signature dynamics technology. Either way the signature must be unique to the person using it, capable of verification, under that person’s sole control, and linked to the document so that it is invalidated if any data in the document are changed. One requirement is technology-specific rather than criteria-based: when a licensee electronically seals only the cover page of a set of drawings, Signature Dynamic Technology shall be used.
Do I need a new Colorado seal when I renew?
No. Architect, professional engineer and professional land surveyor licenses all expire on October 31 of odd-numbered years, and the license number does not change on renewal or on reinstatement of an expired or retired license, so the seal does not have to be recut. An expired or retired license may be reinstated by application and fee within two years. Rule 1.3(A)(3) leaves licensees personally and professionally responsible and accountable for the care, custody, control and use of their seals, and for land surveyors that duty extends to unused monument caps bearing the license number. Nothing requires the seal to be surrendered or destroyed.
Does a Colorado firm need a certificate of authorization number on the drawing?
No. Colorado does not license or register engineering, surveying or architecture firms and issues no certificate of authorization, so no firm number appears on a sealed document and no firm holds a seal. Responsibility attaches to the individual through the responsible charge test in C.R.S. 12-120-216(2) and the scope-limiting note in Rule 1.5(A)(5).
My Colorado seal predates the current rule. Is it still good?
Yes, and the grandfather date depends on which document you read. C.R.S. 12-120-216(1) protects seals held by engineers licensed before July 1, 2004, while Rule 1.5(A)(1) says seals obtained prior to July 1, 2005 are deemed acceptable. The same split appears on the architect side, where the statute says licensed before July 1, 2013 and Rule 1.7(A)(1) says seals obtained prior to September 1, 2015.
