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.2, RSMo (effective August 28, 2026, L. 2026 S.B. 1233) on 21 September 2026 · Updated 21 September 2026
Missouri requires you to have a personal seal and has not yet told anyone what it looks like. Section 327.411.1, RSMo, in the version effective August 28, 2026, reads “Each architect and each professional engineer and each professional land surveyor and each professional landscape architect and each licensed interior designer 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.” The rule that supplies the form, 20 CSR 2030-3.060, has not been amended to cover the credential, so the prescribed form the statute demands does not yet exist.
That matters when you order. 20 CSR 2030-3.060(1) names four legends and four prefixes, being Architect with A, Professional Engineer with PE, Professional Land Surveyor with PLS and Professional Landscape Architect with PLA, and applies its 1-3/4 inch figure by its own words to “Each person licensed as an architect, professional engineer, professional land surveyor, or professional landscape architect.” The word interior does not appear in 20 CSR 2030-3 at all, and the Interior Design Council chapters at 20 CSR 2193-1 and 20 CSR 2193-2 contain no seal rule either.
So the sensible move is to wait rather than to substitute your title into one of the four existing designs. A die that does not match a prescribed design is not the seal the statute asks for, and § 327.411.2 makes whatever you do use “the legal equivalent of the licensee’s signature whenever and wherever used.” Two questions are worth putting to the board before you buy anything: the legend it settles on, and the letter prefix it assigns to your number, since A, PE, PLS and PLA are taken.
Missouri interior designer seal requirements at a glance
| Requirement | Missouri rule | Source |
|---|---|---|
| Seal required | Yes | § 327.411.1 and.2, RSMo (effective August 28, 2026, L. 2026 S.B. 1233) |
| Required elements | No design prescribed by rule yet, Statutory duty to hold a personal seal and Form to be prescribed by the board | § 327.411.1, RSMo |
| Size and shape | Not addressed. The 1-3/4 inch figure in 20 CSR 2030-3.060(1) applies by its own words to “Each person licensed as an architect, professional engineer, professional land surveyor, or professional landscape. | 20 CSR 2030-3.060(1) (by its terms limited to the other four professions) |
| Device allowed | Not addressed. The sentence in 20 CSR 2030-3.060 permitting “an embossing seal, a rubber stamp, or a computer-generated image” is tied to the design in section (1) of that rule, which does not reach interior. | 20 CSR 2030-3.060 |
| Signature and date | Not addressed for this credential. | 20 CSR 2030-3.060(3) |
| What must be sealed | The statute is clear about scope even while the design is missing. | §§ 327.411.1,.4, 327.700, 327.705, RSMo |
| Electronic seal | Not addressed. The four-part digital signature test in 20 CSR 2030-3.060(3) belongs to a rule that does not yet cover interior designers, and Chapter 327, RSMo, prescribes no electronic sealing standard for the. | 20 CSR 2030-3.060(3) |
| Renewal and lapse | Not addressed. Nothing in section 327.411, sections 327.700 to 327.750, RSMo, 20 CSR 2030-3 or 20 CSR 2193 says what becomes of an interior designer’s seal on lapse, revocation or surrender, or whether a license. | §§ 327.411, 327.700 to 327.750, RSMo |
| Firm requirements | Not addressed for this credential. 20 CSR 2030-10.010 governs certificates of authority for corporations rendering architectural, engineering, land surveying and landscape architectural services. | 20 CSR 2030-10.010 (interior design not named) |
| Regulator | The Missouri Board for Architects, Professional Engineers, Professional Land Surveyors, Professional Landscape Architects, and Licensed Interior Designers | Sections 327.011, 327.411 and 327.700 to 327.750, RSMo, Chapter 327 (current versions effective August 28, 2026, L. 2026 S.B. 1233) |
Is a seal required in Missouri?
Missouri now imposes the seal duty on licensed interior designers by statute, and has not yet prescribed the seal. Section 327.411.1, RSMo, in the version effective August 28, 2026, reads “Each architect and each professional engineer and each professional land surveyor and each professional landscape architect and each licensed interior designer 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.” Section 327.411.2 adds that the personal seal of a licensed interior designer “shall be the legal equivalent of the licensee’s signature whenever and wherever used” and makes the owner responsible for the interior design documents. The board rule that supplies the design, 20 CSR 2030-3.060, has not been amended to cover the credential, so the form the statute demands does not yet exist.
What must appear on the seal
- No design prescribed by rule yet
- Statutory duty to hold a personal seal
- Form to be prescribed by the board
There is nothing to specify yet, and guessing is the wrong move. 20 CSR 2030-3.060(1) names four legends and four prefixes, being Architect with A, Professional Engineer with PE, Professional Land Surveyor with PLS and Professional Landscape Architect with PLA. The word interior does not appear anywhere in 20 CSR 2030-3, and the Interior Design Council chapters at 20 CSR 2193-1 and 20 CSR 2193-2 contain no seal rule either. Since section 327.411.1 requires a seal “in a form prescribed by the board”, a die invented from the engineer or architect pattern would not be in the prescribed form, because no form has been prescribed.
Size and shape
Not addressed. The 1-3/4 inch figure in 20 CSR 2030-3.060(1) applies by its own words to “Each person licensed as an architect, professional engineer, professional land surveyor, or professional landscape architect”, and interior designers are not in that sentence. Checked the whole of 20 CSR 2030-3, 20 CSR 2193-1 and 20 CSR 2193-2, and sections 327.411 and 327.700 to 327.750, RSMo. No diameter, shape or construction is stated for this credential anywhere.
Embosser, rubber stamp or digital
Not addressed. The sentence in 20 CSR 2030-3.060 permitting “an embossing seal, a rubber stamp, or a computer-generated image” is tied to the design in section (1) of that rule, which does not reach interior designers. Nothing in Chapter 327, RSMo, names a permitted device for this credential. Wait for the board to amend 20 CSR 2030-3.060 rather than ordering against the four existing designs.
Signing and dating
Not addressed for this credential. The signature and dating mechanics in 20 CSR 2030-3.060(3), including the wet signature rule, the digital signature rule and the scanned signature allowance for PDF, sit in a rule whose design paragraph covers only the other four professions. Section 327.411, RSMo, imposes the seal duty on licensed interior designers but says nothing about how the signature and date accompany it.
The statute now requires the seal; the rule that prescribes seals has not caught up
Section 327.411, RSMo, was amended by S.B. 1233 and the new text took effect on August 28, 2026. The version that ran from 2014 to 2026 required a personal seal of “each architect and each professional engineer and each professional land surveyor and each professional landscape architect”. The current version adds “and each licensed interior designer” to that sentence and to subsections 2 and 3, and section 327.011 now names the board itself for five professions rather than four.
The rule that actually prescribes the seal did not move. 20 CSR 2030-3.060 was last amended in 2018. Its design paragraph still names only Architect, Professional Engineer, Professional Land Surveyor and Professional Landscape Architect, and still lists only the prefixes A, PE, PLS and PLA. The word interior does not appear in the rule at all, and the Interior Design Council chapters at 20 CSR 2193 contain no seal rule either.
That leaves a licensed interior designer in an odd position: a statutory duty to hold a personal seal “in a form prescribed by the board”, and no prescribed form to hold. The answer is to wait for the amendment rather than to have a die cut on the architect pattern with the word Interior substituted. A seal that does not match a prescribed design is not the seal the statute asks for, and section 327.411.2 makes whatever you do use the legal equivalent of your signature.
Two things are worth confirming with the board before you order anything: the legend it settles on, and the letter prefix it assigns to the number, since A, PE, PLS and PLA are all taken.
Which documents must be sealed
The statute is clear about scope even while the design is missing. Section 327.411.1, RSMo, requires the seal on “all final technical submissions”, and section 327.700 defines an “interior technical submission” as the designs, drawings and specifications that establish the scope and quality standards of an interior alteration or construction project. Section 327.411.4 keeps preliminary and incomplete documents outside the duty. Note the limit on the practice itself: section 327.700 excludes structural work, changes to the building envelope, mechanical and electrical systems and other reserved professional practice from licensed interior design, and section 327.705 bars the state and any county, municipality or other political subdivision from requiring a licensed interior designer for residential buildings, remodeling, rehabilitation or construction.
Electronic and digital seals
Not addressed. The four-part digital signature test in 20 CSR 2030-3.060(3) belongs to a rule that does not yet cover interior designers, and Chapter 327, RSMo, prescribes no electronic sealing standard for the credential.
Renewal, lapse and retirement
Not addressed. Nothing in section 327.411, sections 327.700 to 327.750, RSMo, 20 CSR 2030-3 or 20 CSR 2193 says what becomes of an interior designer’s seal on lapse, revocation or surrender, or whether a license number survives reinstatement. Checked all four.
Firm requirements
Not addressed for this credential. 20 CSR 2030-10.010 governs certificates of authority for corporations rendering architectural, engineering, land surveying and landscape architectural services. Whether an interior design practice needs a certificate of authority is not addressed in that rule. No firm seal exists for any Missouri design profession and no firm number goes on a submission.
What to check before you order
Hold off. Missouri requires you to have a personal seal but has not yet told anyone what it looks like. Section 327.411.1, RSMo, says the form is prescribed by the board, and 20 CSR 2030-3.060 still lists only Architect, Professional Engineer, Professional Land Surveyor and Professional Landscape Architect with the prefixes A, PE, PLS and PLA. Do not have a die cut by substituting your title into one of those four designs, and do not accept a supplier’s house pattern. Ask the board when it expects to amend 20 CSR 2030-3.060, and order once the legend, the prefix and the diameter are published.
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Frequently asked questions
Does Missouri require licensed interior designers to have a seal?
Yes. Section 327.411.1, RSMo, as it stands effective August 28, 2026, puts licensed interior designers in the same sentence as architects, professional engineers, professional land surveyors and professional landscape architects, requiring each to have a personal seal in a form prescribed by the board and to affix it to all final technical submissions. The duty is live; the design is what is missing.
What does a Missouri licensed interior designer seal look like?
No design has been prescribed for it. 20 CSR 2030-3.060(1) lists four legends and four prefixes and interior designer is not among them, and 20 CSR 2193-1 and 20 CSR 2193-2 contain no seal rule. Since § 327.411.1 requires a seal “in a form prescribed by the board,” a die invented from the architect or engineer pattern would not be in the prescribed form, because no form has been prescribed.
What size is a Missouri interior designer seal?
No diameter has been set for this credential. The 1-3/4 inch figure in 20 CSR 2030-3.060(1) applies by its own terms to the other four professions. No dimension, shape or construction is stated for licensed interior designers anywhere in 20 CSR 2030-3, 20 CSR 2193-1, 20 CSR 2193-2 or §§ 327.411 and 327.700 to 327.750, RSMo.
Should I order a Missouri interior designer seal now?
Holding off is the safer course until the board publishes the design. Substituting your title into one of the four existing patterns produces a device that matches no prescribed form, and a supplier’s house pattern has the same problem. Ask the board when it expects to amend 20 CSR 2030-3.060, and order once the legend, the prefix and the diameter are published. Nothing stops you carrying a plain name and firm block in the meantime, provided it does not imitate one of the four prescribed designs.
Which documents does a Missouri licensed interior designer seal?
All final technical submissions, under § 327.411.1, RSMo. Section 327.700 defines an “interior technical submission” as the designs, drawings and specifications that establish the scope and quality standards of an interior alteration or construction project, and § 327.411.4 keeps preliminary and incomplete documents outside the duty.
What falls outside licensed interior design practice in Missouri?
Section 327.700 excludes structural work, changes to the building envelope, mechanical and electrical systems and other reserved professional practice from licensed interior design. Section 327.705 adds a separate limit on the demand side: the state and any county, municipality or other political subdivision may not require a licensed interior designer for residential buildings, remodeling, rehabilitation or construction.
What device does Missouri permit for an interior designer seal?
The sentence in 20 CSR 2030-3.060 permitting “an embossing seal, a rubber stamp, or a computer-generated image” is tied to the design paragraph in section (1) of that rule, which does not reach interior designers, and nothing in Chapter 327, RSMo, names a permitted device for this credential. The device question is part of what the board still has to settle.
How do signature and date work with a Missouri interior designer seal?
The mechanics in 20 CSR 2030-3.060(3), including the wet signature rule, the digital signature rule and the scanned signature allowance for PDF, sit in a rule whose design paragraph covers only the other four professions. Section 327.411, RSMo, imposes the seal duty on licensed interior designers without saying how the signature and date accompany it, which is another reason to confirm the mechanics with the board when the design is published.
Can I seal Missouri interior design documents electronically?
The four-part digital signature test in 20 CSR 2030-3.060(3) belongs to a rule that does not yet cover this credential, and Chapter 327, RSMo, prescribes no electronic sealing standard for it. Treating the paper and electronic routes as one open question and resolving both with the board at the same time is the cleaner approach.
What happens to a Missouri interior designer seal on lapse or revocation?
Nothing in § 327.411, §§ 327.700 to 327.750, RSMo, 20 CSR 2030-3 or 20 CSR 2193 states what becomes of the seal on lapse, revocation or surrender, or whether a license number survives reinstatement. The number question is worth asking before you order, because a number that changes on reinstatement would mean recutting the die.
Does a Missouri interior design firm need a certificate of authority?
20 CSR 2030-10.010 governs certificates of authority for corporations rendering architectural, engineering, land surveying and landscape architectural services, and does not name interior design. Whether an interior design practice needs one is unresolved in that rule. What is settled is that no firm seal exists for any Missouri design profession and no firm number goes on a submission.
