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 Missouri Board for Architects, Professional Engineers, Professional Land Surveyors, Professional Landscape Architects, and Licensed Interior Designers and § 327.411.1 and.4, RSMo (current version effective August 28, 2026) on 21 September 2026 · Updated 21 September 2026
The lower arc says ARCHITECT and the number carries a capital A in front of it. 20 CSR 2030-3.060(1) writes one design for four professions and changes only two things between them: STATE OF MISSOURI arcs across the top of the ring for everyone, the lower arc swaps between Architect, Professional Engineer, Professional Land Surveyor and Professional Landscape Architect, and the letter in front of the license number swaps between A, PE, PLS and PLA. Architects get the shortest legend in the set, a single word, where the other three all carry Professional.
A national template that prints REGISTERED ARCHITECT on the lower arc and a plain number inside is wrong on both counts. The rest is arithmetic: the circle is 1-3/4 inches, stated once, with no tolerance and no separate inner-circle dimension, and the lettering is roman capitals, so a script or mixed-case ring is wrong too.
Missouri gives the seal unusual weight. Section 327.411.2, RSMo, provides that it “shall be the legal equivalent of the licensee’s signature whenever and wherever used.”
Missouri architect seal requirements at a glance
| Requirement | Missouri rule | Source |
|---|---|---|
| Seal required | Yes | § 327.411.1 and.4, RSMo (current version effective August 28, 2026) |
| Required elements | Two concentric circles, State of Missouri, Architect, Your name as licensed and Your license number prefixed A | 20 CSR 2030-3.060(1) |
| Size and shape | One and three-quarters inches (1-3/4 inches) in diameter. 20 CSR 2030-3.060(1) requires each licensee to “secure a seal one and three-quarters inches (1 3/4″) in diameter of the following design”. | 20 CSR 2030-3.060(1) |
| Device allowed | All three common devices are legal. 20 CSR 2030-3.060 provides that “The seal may be in the form of an embossing seal, a rubber stamp, or a computer-generated image, identical in size, design and content with the provisions of section (1) above.” The safe buy is a 1-3/4 inch inked rubber stamp, because it satisfies the paper case outright and because the computer-generated image has to match it in size, design and content anyway. | 20 CSR 2030-3.060 |
| Signature and date | Missouri accepts three signature forms and ties the date to the sealing event. | 20 CSR 2030-3.060(3) |
| What must be sealed | Everything final. | § 327.411.1,.3,.4, RSMo |
| Electronic seal | No named technology and no named cryptographic standard. 20 CSR 2030-3.060 sets functional criteria instead: the digital signature must be “unique to, and under the sole control of the person using it; it must also be capable of verification and be linked to a document in such manner that the digital signature is invalidated if any data on the document is altered”. | 20 CSR 2030-3.060(3) |
| Renewal and lapse | Not addressed. Neither section 327.411, RSMo, nor 20 CSR 2030-3 says what happens to the seal when a license lapses, is revoked or is surrendered, and neither requires the device to be destroyed or turned in. Checked. | § 327.411, RSMo, and 20 CSR 2030-3 (silent) |
| Firm requirements | The firm needs a certificate of authority, but not a seal and not a number on the drawing. | 20 CSR 2030-10.010 |
| Regulator | The Missouri Board for Architects, Professional Engineers, Professional Land Surveyors, Professional Landscape Architects, and Licensed Interior Designers | Sections 327.011 and 327.411, RSMo, Chapter 327 (current versions effective August 28, 2026, L. 2026 S.B. 1233) |
Is a seal required in Missouri?
The duty sits in statute and is absolute for finished work. Section 327.411.1, RSMo, provides that each architect “shall have a personal seal in a form prescribed by the board, and he or she shall affix the seal to all final technical submissions”, and defines technical submissions to include “drawings, specifications, plats, surveys, exhibits, reports, and certifications of construction”. Section 327.411.2 gives the seal unusual weight: it “shall be the legal equivalent of the licensee’s signature whenever and wherever used”. The board rule, 20 CSR 2030-3.060, prescribes the form and the signature and date mechanics. Preliminary work is carved out by section 327.411.4, which says nothing in the section or any board rule “shall require any professional to seal preliminary or incomplete documents”.
What must appear on the seal
- Two concentric circles
- State of Missouri
- Architect
- Your name as licensed
- Your license number prefixed A
The design is fixed and the rule states it word for word. 20 CSR 2030-3.060(1) requires “two concentric circles between which appear in roman capital letters, the words, ‘State of Missouri’ on the upper part of the seal and either ‘Architect,’ or ‘Professional Engineer,’ or ‘Professional Land Surveyor’ or ‘Professional Landscape Architect,’ as the case may be, on the lower part, and within the inner circle the name of the licensee, together with his/her license number preceded by the roman capital letter(s) A for Architect, PE for Professional Engineer, PLS for Professional Land Surveyor or PLA for Professional Landscape Architect.” So the lower arc reads the single word Architect, not Registered Architect and not Licensed Architect, and the number carries a capital A in front of it. Roman capitals are specified, so a script or mixed-case ring is wrong. Interns and individuals in-training are excluded by the same subsection and get no seal. No expiration date and no board emblem belong on the face.
Size and shape
One and three-quarters inches (1-3/4 inches) in diameter. 20 CSR 2030-3.060(1) requires each licensee to “secure a seal one and three-quarters inches (1 3/4″) in diameter of the following design”. That is a single stated figure, not a range and not a minimum, and the rule gives no tolerance and does not separately dimension the inner circle.
Embosser, rubber stamp or digital
All three common devices are legal. 20 CSR 2030-3.060 provides that “The seal may be in the form of an embossing seal, a rubber stamp, or a computer-generated image, identical in size, design and content with the provisions of section (1) above.” The safe buy is a 1-3/4 inch inked rubber stamp, because it satisfies the paper case outright and because the computer-generated image has to match it in size, design and content anyway. An embosser alone is legal but leaves a blind impression that reproduces poorly on the scanned submittals the same rule contemplates.
Signing and dating
Missouri accepts three signature forms and ties the date to the sealing event. The rule requires the licensee to “affix his/her signature and place the date when the document was originally sealed, at the minimum”. For hand drawings and printed documents that means “a handwritten ‘wet signature’ identification containing the name of the person who applied it”. For an electronic document in its native format it means “a digital signature with an electronic authentication process attached to or logically associated with the document”. For PDF and similar formats, “a scanned signature is acceptable if it is an accurate depiction of the licensee’s actual signature”. Signing across the face of the seal is not addressed anywhere in 20 CSR 2030-3.060 or in section 327.411, RSMo, so the local habit of writing across the seal is practice rather than rule.
The lower arc says Architect and the number carries a capital A
Missouri writes one design for four professions and changes only two things between them. 20 CSR 2030-3.060(1) puts “State of Missouri” on the upper part of the ring for everyone, then swaps the lower arc between Architect, Professional Engineer, Professional Land Surveyor and Professional Landscape Architect, and swaps the letter in front of the license number between A, PE, PLS and PLA.
Both halves catch buyers out. Architects get the shortest legend in the set, a single word, where the other three all carry Professional. And the prefix is part of the number: a Missouri architect’s inner circle reads A followed by the number, not the bare digits. A national template that prints REGISTERED ARCHITECT on the lower arc and a plain number inside is wrong on both counts.
The rest is arithmetic. The circle is 1-3/4 inches, stated once, with no tolerance and no separate inner-circle dimension, and the lettering is roman capitals. Rubber stamp, embosser and computer-generated image are all lawful, and the rule requires them to be identical in size, design and content, so cut one master and derive the digital image from it.
Which documents must be sealed
Everything final. Section 327.411.1, RSMo, reaches all final technical submissions, expressly including drawings, specifications, plats, surveys, exhibits, reports and certifications of construction. For bound work the rule allows one sealing point: the licensee “may sign, seal, and date the title page, an index page, or a seals page on bound multiple page documents”, provided the signed page clearly identifies the other pages it covers. Preliminary or incomplete work is excused from sealing by section 327.411.4 but not from labeling, and the rule requires the legend “The information on this document is preliminary or incomplete, not for construction, recording purposes, or implementation” in an obvious, easily readable location. Sealing another person’s work is barred: “The signing and sealing of technical submissions not prepared by the licensee or under his/her immediate personal supervision is prohibited.”
Electronic and digital seals
No named technology and no named cryptographic standard. 20 CSR 2030-3.060 sets functional criteria instead: the digital signature must be “unique to, and under the sole control of the person using it; it must also be capable of verification and be linked to a document in such manner that the digital signature is invalidated if any data on the document is altered”. That is the familiar four-part test, met in practice by a certificate-based digital signature, but the rule names no issuer, no certificate authority and no algorithm. Note the split: a full digital signature is required only for documents delivered in a native electronic format, while a scanned image of the real signature is enough for a PDF.
Renewal, lapse and retirement
Not addressed. Neither section 327.411, RSMo, nor 20 CSR 2030-3 says what happens to the seal when a license lapses, is revoked or is surrendered, and neither requires the device to be destroyed or turned in. Checked the current text of section 327.411, a scan of Chapter 327, RSMo, for the word seal, and the whole of 20 CSR 2030-3. The practical bar comes from the prohibition elsewhere in Chapter 327 on practicing or holding out without a current license, and from section 327.411.2, which makes the seal the legal equivalent of the signature. Nothing found says the license number changes on reinstatement, so confirm the number before reordering.
Firm requirements
The firm needs a certificate of authority, but not a seal and not a number on the drawing. A corporation rendering architectural, engineering, land surveying or landscape architectural services in Missouri applies for a certificate of authority under 20 CSR 2030-10.010, which covers the application, the managing agent and renewal. Neither that chapter nor 20 CSR 2030-3.060 requires the certificate number or a corporate seal on technical submissions. The individual licensee’s personal seal carries the document, and section 327.411.1 keeps personal responsibility with that licensee whether or not another licensee drafted the sheet.
What to check before you order
Order a 1-3/4 inch die with two concentric circles and roman capitals throughout. STATE OF MISSOURI arcs across the top of the annular space and ARCHITECT across the bottom. Inside the inner circle put your name as licensed and your license number with the capital letter A in front of it. No expiration date, no board emblem, no discipline line. Rubber stamp, embosser and computer-generated image are all permitted and have to be identical in size, design and content, so have one master design cut and derive the digital image from it. Missouri asks no proof of licensure at the counter and requires no imprint filing with the board.
Browse architect stamps and seals.
Frequently asked questions
Is an architect seal required in Missouri?
Yes, on everything final. Section 327.411.1, RSMo, provides that each architect “shall have a personal seal in a form prescribed by the board, and he or she shall affix the seal to all final technical submissions,” and defines technical submissions to include “drawings, specifications, plats, surveys, exhibits, reports, and certifications of construction.” Preliminary work is carved out by section 327.411.4, which says nothing in the section or any board rule “shall require any professional to seal preliminary or incomplete documents.”
What has to appear on a Missouri architect seal?
Five elements under 20 CSR 2030-3.060(1): two concentric circles, State of Missouri on the upper part of the ring, Architect on the lower part, your name as licensed inside the inner circle, and your license number preceded by the roman capital letter A. Interns and individuals in-training are excluded by the same subsection and get no seal. No expiration date and no board emblem belong on the face.
What size is a Missouri architect seal?
One and three-quarters inches in diameter. 20 CSR 2030-3.060(1) requires each licensee to “secure a seal one and three-quarters inches (1 3/4″) in diameter of the following design.” That is a single stated figure, not a range and not a minimum, with no tolerance and no separate inner-circle dimension.
Can I use an embosser in Missouri?
Yes. The rule provides that “The seal may be in the form of an embossing seal, a rubber stamp, or a computer-generated image, identical in size, design and content with the provisions of section (1) above.” A 1-3/4 inch inked rubber stamp is the practical buy, because it satisfies the paper case outright and the computer-generated image has to match it in size, design and content anyway. Cut one master and derive the digital image from it. An embosser alone is legal but leaves a blind impression that reproduces poorly on scanned submittals.
What signature does Missouri accept?
Three forms, tied to the format. For hand drawings and printed documents, “a handwritten ‘wet signature’ identification containing the name of the person who applied it.” For an electronic document in its native format, “a digital signature with an electronic authentication process attached to or logically associated with the document.” For PDF and similar formats, “a scanned signature is acceptable if it is an accurate depiction of the licensee’s actual signature.” The rule also requires the licensee to place the date when the document was originally sealed, at the minimum.
Do I have to sign across a Missouri seal?
Signing across the face of the seal is not addressed anywhere in 20 CSR 2030-3.060 or in section 327.411, RSMo. The local habit of writing across the seal is practice rather than rule.
Do I have to seal every page in Missouri?
Not for bound work. The rule allows one sealing point: the licensee “may sign, seal, and date the title page, an index page, or a seals page on bound multiple page documents,” provided the signed page clearly identifies the other pages it covers.
How do I label preliminary work in Missouri?
Section 327.411.4 excuses preliminary or incomplete work from sealing but not from labeling, and the rule requires the legend “The information on this document is preliminary or incomplete, not for construction, recording purposes, or implementation” in an obvious, easily readable location.
What does Missouri require of a digital signature?
Functional criteria rather than a named technology. The digital signature must be “unique to, and under the sole control of the person using it; it must also be capable of verification and be linked to a document in such manner that the digital signature is invalidated if any data on the document is altered.” No issuer, certificate authority or algorithm is named. Note the split: a full digital signature is required only for documents delivered in a native electronic format, while a scanned image of the real signature is enough for a PDF.
Can I seal work someone else prepared in Missouri?
No. The rule states that “The signing and sealing of technical submissions not prepared by the licensee or under his/her immediate personal supervision is prohibited.”
What happens to my Missouri seal if my license lapses?
Neither section 327.411, RSMo, nor 20 CSR 2030-3 says what happens to the seal when a license lapses, is revoked or is surrendered, and neither requires the device to be destroyed or turned in. A scan of Chapter 327 for the word seal and the whole of 20 CSR 2030-3 read the same way. The practical bar comes from the prohibition elsewhere in Chapter 327 on practicing or holding out without a current license, and from section 327.411.2, which makes the seal the legal equivalent of the signature. Nothing states whether the license number changes on reinstatement, so confirm the number before reordering.
Does a Missouri architecture firm get a seal?
No, though it does need a certificate of authority. A corporation rendering architectural, engineering, land surveying or landscape architectural services in Missouri applies under 20 CSR 2030-10.010, which covers the application, the managing agent and renewal. Neither that chapter nor 20 CSR 2030-3.060 requires the certificate number or a corporate seal on technical submissions. Your personal seal carries the document, and section 327.411.1 keeps personal responsibility with you whether or not another licensee drafted the sheet.
