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 Board for Professional Engineers, Land Surveyors, and Geologists and Cal. Bus. & Prof. Code § 6764 on 21 September 2026 · Updated 21 September 2026
California lets you buy a rubber stamp of your seal and forbids a rubber stamp of your signature. Section 411(f) of the Board rules prohibits three products by name: blank forms preprinted with the seal or the signature, decals of either, and a rubber stamp of the signature. The seal itself may be an inked stamp, an embosser or a computer generated image without any difficulty.
The size is a floor with no stated ceiling: not less than one and one half inches in diameter, under section 411(a) for engineers and 411(b) for land surveyors. A die cut slightly under 1.5 inches by a vendor tolerance is out of compliance.
One more thing worth knowing before you order: no expiration date is a required element. Section 411(a) lists five items and then says the seal shall bear at minimum those elements, and the certificate number does not change at renewal, so a renewal does not make an existing seal stale.
California PE seal requirements at a glance
| Requirement | California rule | Source |
|---|---|---|
| Seal required | Yes | Cal. Bus. & Prof. Code § 6764 |
| Required elements | Your name as it appears on your certificate; Your certificate or authority number; Your branch or authority of engineering; Professional Engineer, Registered Professional Engineer, or Licensed Professional Engineer within the top border; State of California within the bottom border | Cal. Code Regs. tit. 16, § 411(a) |
| Size and shape | Not less than one and one half inches in diameter. | Cal. Code Regs. tit. 16, § 411(a), (b) |
| Device allowed | All three device families are legal. | Cal. Code Regs. tit. 16, § 411(e) |
| Signature and date | A signature is always required alongside the seal, and it must be a real signature or an electronic one, never a stamped one. | Cal. Code Regs. tit. 16, § 411(e), (f), (g)(3), (h) |
| What must be sealed | Section 411(g)(1) reaches “All professional engineering plans, specifications, reports, or documents,” which must be signed and sealed so that all work can be clearly attributed to the licensee in responsible charge. | Cal. Bus. & Prof. Code §§ 6733, 6735 |
| Electronic seal | The Board permits an electronic seal and an electronic signature but names no technology. | Cal. Code Regs. tit. 16, § 411(e) |
| Renewal and lapse | Sealing stops the moment the certificate does. | Cal. Bus. & Prof. Code § 6733 |
| Firm number on documents | Not applicable in the certificate of authorization sense. | Cal. Bus. & Prof. Code § 6738(h)(1) |
| Licensing board | The Board for Professional Engineers, Land Surveyors, and Geologists | Professional Engineers Act, Cal. Bus. & Prof. Code §§ 6700 to 6799, 2026 edition published by the Board; Board Rules, Cal. Code Regs. tit. 16, §§ 400 to 476, 2026 edition published by the Board; California Secretary of State digital signature regulations, Cal. Code Regs. tit. 2, §§ 22000 to 22005 |
Rules for other states are on PE stamp requirements by state.
Is a seal required in California?
California requires a seal California splits the duty in two. The statute creates the seal: Business and Professions Code section 6764 provides that “Each professional engineer licensed under this chapter shall, upon licensure, obtain a seal or stamp of a design authorized by the board bearing the licensee’s name, number of his or her certificate or authority, the legend ‘professional engineer’ and the designation of the particular branch or authority in which he or she is licensed.” The statute says nothing about what the seal looks like beyond that. The design, the diameter and the signing and dating mechanics all sit in the Board rule, California Code of Regulations title 16 section 411, which is the section a stamp buyer actually has to satisfy. The duty to put the seal on documents sits in section 411(g) for engineering generally and in Business and Professions Code section 6735 for civil engineering work.
What must appear on the seal
- Your name as it appears on your certificate
- Your certificate or authority number
- Your branch or authority of engineering
- Professional Engineer, Registered Professional Engineer, or Licensed Professional Engineer within the top border
- State of California within the bottom border
An abbreviated given name or a combination of initials is allowed, provided the surname on file with the Board appears on the seal and in the signature, under section 411(d). No license expiration date and no renewal date is a required element. Section 411(a) closes with “The seal shall be of a design similar to those shown below and shall bear at minimum those elements specified above,” so an expiration date is at most permitted extra content, never a condition of validity. Three things are flatly prohibited by section 411(f): preprinting blank forms with the seal or the signature, decals of the seal or the signature, and a rubber stamp of the signature. Template stamp listings get this backwards. A rubber stamp of the seal is legal in California. A rubber stamp of the handwritten signature is not, and a signature plate sold as a convenience item is an enforcement problem for the licensee who uses it.
Size and shape
Not less than one and one half inches in diameter. That is a floor with no stated ceiling, and it applies to the land surveyor seal under section 411(b) on the same terms as the engineer seal under section 411(a). A nominal 1.5 inch die is compliant at the limit, so a seal cut slightly undersized by a vendor tolerance is not.
Embosser, rubber stamp or digital
All three device families are legal. Section 411(e) provides that “The seal shall be capable of leaving a permanent ink representation, a permanent impression, or an electronically-generated representation on the documents.” Permanent ink representation covers a rubber stamp or self inking stamp, permanent impression covers an embosser, and electronically-generated representation covers a computer generated facsimile applied to an electronic file. The safe buy is an inked rubber or self inking stamp. An embosser alone satisfies the rule but an unfilled embossed impression does not survive scanning or plan reproduction, which is how most California plan sets are actually transmitted.
Signing and dating
A signature is always required alongside the seal, and it must be a real signature or an electronic one, never a stamped one. Section 411(e) permits that “The signature may be applied to the documents electronically,” while section 411(f) prohibits “the use of a rubber stamp of the signature.” The date is the date of signing and sealing, not the license expiration date, and section 411(h) fixes its placement: “Each licensee shall include the date of signing and sealing immediately below or next to the signature and seal.” Nothing in section 411 requires the signature to cross, overlap or run through the seal impression. Section 411(g)(3) adds that where two or more licensees are in responsible charge, each signature and seal goes on the document with a notation describing the work done under each licensee’s responsible charge.
California bans a stamp of your signature, not a stamp of your seal
Section 411(f) prohibits three specific products: blank forms preprinted with the seal or signature, decals of the seal or signature, and a rubber stamp of the signature. Every one of those is something a stamp shop can physically make, and two of them are routinely sold elsewhere as time savers. The seal itself may be a rubber stamp, an embosser or a computer generated image without any problem at all. It is the signature that must stay handwritten or electronic.
Which documents must be sealed
Section 411(g)(1) reaches “All professional engineering plans, specifications, reports, or documents,” which must be signed and sealed so that all work can be clearly attributed to the licensee in responsible charge. For civil engineering, section 6735 is more specific: interim documents must be marked with a notation such as preliminary, not for construction, for plan check only, or for review only, and final documents released for construction carry the signature, the seal or stamp and the date of signing on each sheet of the plans, and at minimum on the title sheet, cover sheet or signature sheet of specifications, calculations and reports. Section 6733 makes it unlawful to stamp or seal after the certificate has expired or has been suspended or revoked.
Electronic and digital seals
The Board permits an electronic seal and an electronic signature but names no technology. Section 411(e) is the whole of it: an electronically-generated representation of the seal, and a signature that “may be applied to the documents electronically.” A word by word search of Board Rules sections 400 through 476 turns up the words electronic and electronically only in section 411(e). There is no Board rule requiring a certificate authority, a tamper evident container, a hash or a named vendor. Where a California public entity chooses to accept a digital signature, the controlling standard is Government Code section 16.5 and the Secretary of State regulations at title 2 sections 22000 through 22005, which approve public key cryptography and signature dynamics. That standard binds the accepting public entity, not the engineer, and it is not a Board requirement.
Renewal, lapse and retirement
Sealing stops the moment the certificate does. Section 6733 provides that “It is unlawful for anyone to stamp or seal any plans, specifications, plats, reports, or other documents with the seal after the certificate of the registrant, named thereon, has expired or has been suspended or revoked, unless the certificate has been renewed or reissued.” Because the certificate number is one of the required seal elements and the expiration date is not, a renewal does not make an existing seal stale and does not require a new device. Neither section 6733 nor section 411 requires a lapsed, suspended or revoked licensee to surrender or destroy the seal, and neither addresses issuance of a different certificate number on reinstatement. Not addressed in the Professional Engineers Act or in Board Rules sections 400 through 476.
Firm registration
Not applicable in the certificate of authorization sense. California does not issue an engineering firm certificate of authorization and no firm number belongs on a sealed document. What California requires instead is a filing: Business and Professions Code section 6738(h)(1) provides that “A current organization record shall be filed with the board for all businesses engaged in rendering civil, electrical, or mechanical engineering services.” That record lives at the Board, not in the title block.
What to check before you order
You may buy your seal anywhere. Section 411(c) says plainly that “The seal may be obtained by the licensee from any source,” and nobody has to see proof of your licensure before making it. Your device has to be at least one and one half inches across, with one of the three permitted title legends in the top border, State of California in the bottom border, and your name, certificate number and branch in the center. An abbreviated first name or initials is fine so long as your surname matches Board records. Section 411(f) prohibits a signature stamp, a seal decal and preprinted forms bearing your seal, so do not order any of the three.
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Frequently asked questions
Is a PE stamp required in California?
Yes. Business and Professions Code section 6764 requires each professional engineer, upon licensure, to obtain a seal or stamp of a design authorized by the board. The duty to apply it sits in Board rule section 411(g) for engineering generally, and in Business and Professions Code section 6735 for civil engineering work.
What size is a California PE stamp?
Not less than one and one half inches in diameter. That is a minimum with no stated maximum, and it applies to the land surveyor seal on the same terms as the engineer seal. A nominal 1.5 inch die is compliant at the limit, so watch manufacturing tolerance.
What has to appear on a California PE seal?
Five elements under section 411(a): your name as it appears on your certificate; your certificate or authority number; your branch or authority of engineering; the words Professional Engineer, Registered Professional Engineer or Licensed Professional Engineer within the top border; and State of California within the bottom border. An abbreviated given name or a combination of initials is allowed under section 411(d), so long as the surname on file with the Board appears on the seal and in the signature.
Can I buy a stamp of my signature in California?
No. Section 411(f) prohibits the use of a rubber stamp of the signature, along with seal or signature decals and blank forms preprinted with the seal or signature. Section 411(e) does allow the signature to be applied electronically. A signature plate sold as a convenience item is an enforcement problem for the licensee who uses it.
Does my California seal need my license expiration date?
No. The expiration date is not among the five required elements in section 411(a), and the section closes by saying the seal shall bear at minimum those elements, so an expiration date is at most permitted extra content. A California seal with no expiration date on it is compliant.
Embosser, rubber stamp or electronic in California?
All three. Section 411(e) requires the seal to be capable of leaving a permanent ink representation, a permanent impression, or an electronically generated representation. An inked or self-inking stamp is the practical buy, because an unfilled embossed impression does not survive scanning or plan reproduction, which is how most California plan sets move.
Where do the signature and date go on a California document?
Section 411(h) requires the date of signing and sealing immediately below or next to the signature and seal. That is the date you sign, not the license expiration date. Nothing in section 411 requires the signature to cross, overlap or run through the seal. Where two or more licensees are in responsible charge, section 411(g)(3) requires each signature and seal on the document with a notation describing the work done under each licensee’s responsible charge.
Which California documents have to be signed and sealed?
Section 411(g)(1) reaches all professional engineering plans, specifications, reports or documents, so that all work can be clearly attributed to the licensee in responsible charge. For civil engineering, section 6735 is more specific: interim documents are marked with a notation such as preliminary, not for construction, for plan check only or for review only, and final documents released for construction carry the signature, the seal or stamp and the date of signing on each sheet of the plans, and at minimum on the title, cover or signature sheet of specifications, calculations and reports.
What digital signature standard does the California Board require?
None. Section 411(e) permits an electronically generated representation of the seal and a signature applied electronically, and that is the whole of it; the words electronic and electronically appear nowhere else in Board Rules sections 400 through 476. There is no Board rule requiring a certificate authority, a tamper evident container, a hash or a named vendor. Where a California public entity chooses to accept a digital signature, the controlling standard is Government Code section 16.5 and the Secretary of State regulations at title 2 sections 22000 through 22005, which approve public key cryptography and signature dynamics. That standard binds the accepting public entity, not the engineer.
Does a California firm number go on a sealed document?
No. California does not issue an engineering firm certificate of authorization, so there is no firm number for the title block. What the state requires instead is a filing: Business and Professions Code section 6738(h)(1) requires a current organization record to be filed with the board for all businesses rendering civil, electrical or mechanical engineering services. That record lives at the Board.
Do I need a new California seal when I renew?
No. The certificate number is a required element and the expiration date is not, and the number does not change at renewal. What does matter is the license behind the seal: section 6733 makes it unlawful to stamp or seal after the certificate has expired or has been suspended or revoked, unless it has been renewed or reissued. Neither section 6733 nor section 411 requires a lapsed or revoked licensee to surrender or destroy the device, and neither addresses whether a different certificate number issues on reinstatement.
Where can I buy a California PE seal?
Anywhere. Section 411(c) says the seal may be obtained by the licensee from any source, and California imposes no proof of licensure duty on the vendor.
