An Illinois professional engineer seal must be reproducible and must carry the legend Licensed Professional Engineer of Illinois, your name and your license number. Beside it go your written signature, the date you signed and your license expiration date. A computer generated seal is allowed, but an embosser alone cannot meet the reproducibility requirement. This page covers the seal face, devices, size, signing order, sealed documents, renewal and ordering.
Engineer Seal Stamps compliance desk. Checked against 225 ILCS 325/14 and 325/15(a) and the State Board of Professional Engineers. Sources read September 2026.
| Requirement | What the rule says | Source |
|---|---|---|
| Name | Required on the seal face. | 225 ILCS 325/14 and 325/15(a) |
| License number | Required on the seal face. | 225 ILCS 325/14 and 325/15(a) |
| Legend | Licensed Professional Engineer of Illinois. | 225 ILCS 325/14 and 325/15(a) |
| Items placed beside the seal | Your written signature, the signing date and your license expiration date. | 225 ILCS 325/14 and 325/15(a) |
| Sequence | Seal first, followed by signature, signing date and expiration date. | 225 ILCS 325/14 and 325/15(a) |
| Device test | The seal has to be reproducible. A computer generated seal qualifies; an embosser on its own does not. | 225 ILCS 325/14 |
| Size and shape | No diameter and no shape stated. | Not addressed in the cited rules |
| Documents to seal | Technical submissions, meaning project-defining designs, drawings and specifications along with related calculations, studies and technical reports. | 225 ILCS 325/15(a) and (d) |
| Electronic seal and signature | Both may be computer generated. No particular technology is required. | 225 ILCS 325/14 |
| License cycle | Individual licenses end on November 30 in odd-numbered years and renew for two years. Seal use after a lapse is not addressed. | 68 Ill. Adm. Code 1380.310(a), (c) and (d) |
To compare Illinois with every other jurisdiction, see our table of professional engineer seal requirements by state.
What wording does an Illinois PE seal carry?
Three items: your name, your license number and the phrase Licensed Professional Engineer of Illinois. The other required items, your signature and two dates, go next to the seal rather than inside it, under 225 ILCS 325/14 and 325/15(a).
Keeping the face to those three items means the die does not go out of date when your license cycle turns over. The expiration date changes every two years, so it belongs in the block beside the seal where you can update it, not cut into rubber. For layout ideas, see our post on Illinois PE stamp design.
Why does Illinois insist on a reproducible seal?
Because the statute requires one. 225 ILCS 325/14 calls for a reproducible seal and permits a computer generated version, and the board rule speaks of a reproducible seal or facsimile. A copy of your sheet has to show the seal, so a bare embosser cannot be your only device.
An inked rubber stamp and a computer generated image both leave a mark that copies and scans pick up. A blind embossed impression, pressed into the paper with no ink, does not. Our post on Illinois engineer embossers and stamps has more on both device types.
What size is an Illinois PE stamp?
The cited Illinois law states no diameter and no shape. Illinois engineer seals are manufactured at 1-5/8 inches, and that figure is a production size, not a dimension drawn from 225 ILCS 325/14 or the board rules.
With no size to meet, the practical test is whether the seal still reads after copying. A 1-5/8 inch face gives your name, number and legend room to stay clear on reduced prints and scans.
What goes next to the seal, and in what order?
Illinois sets a sequence: the seal, then your written signature, then the date you signed, then your license expiration date. All three items that follow the seal sit adjacent to it, under 225 ILCS 325/14 and 325/15(a).
Two dates appear, and they answer different questions. The signing date records when you signed that document. The expiration date marks the end of your current license term, which falls on November 30 of an odd-numbered year for every individual Illinois PE. For more on these items, see our post on Illinois PE stamp requirements.
Which Illinois documents need the seal?
Technical submissions. By statute, the term reaches designs, drawings and specifications setting out a project's scope and the quality expected of its materials, equipment, workmanship and construction systems, plus the calculations, studies and technical reports you produce in practice.
Read that definition broadly when you assemble a submission. Calculations and reports count alongside drawings under 225 ILCS 325/15(a) and (d), so the seal belongs on the whole package, not the drawing set alone. Our post on why the Illinois PE stamp matters adds background.
Can an Illinois engineer seal and sign electronically?
Yes. Under 225 ILCS 325/14, the seal and the signature may each be computer generated, and Illinois does not name any particular technology for producing either one, which leaves the method to you.
Whatever software you use, the output still has to be a reproducible seal image, and the same items still belong next to it: the signature, the signing date and the expiration date. Build those into your electronic title block template once so every sheet carries them.
How does the Illinois renewal cycle affect sealed work?
Individual PE licenses end on November 30 in odd-numbered years and renew for two years at a time. The cited rules do not separately address using the seal after a lapse, but the expiration date you write beside the seal changes with each cycle.
Update the expiration entry on your title block templates as soon as you renew, so drawings issued in December show the new date. A seal face that carries only your name, number and legend needs no change at renewal, which is one more reason to keep dates off the die.
What should you send when ordering an Illinois PE seal?
Your name and license number as they appear on your license, and confirmation that the legend reads Licensed Professional Engineer of Illinois. Decide on the device before you order, keeping in mind that it must produce a reproducible impression.
Leave the signature and both dates off the die, since Illinois places them beside the seal. Our post on Illinois PE stamp guidelines works well as a companion checklist.
How can you test an Illinois stamp for reproducibility?
Stamp a test sheet, then photocopy and scan it at the reduction your plan sets use. If the name, number and legend read cleanly on the copy, the impression passes the practical test that the reproducible seal requirement sets up.
An over-inked die can blur fine letters on the copy even when the original looks acceptable, so clean the stamp and test again before a submission goes out.
Frequently asked questions
Does the Illinois seal have to be a particular shape?
The cited statute and rules state no shape. The 1-5/8 inch size Illinois seals are manufactured at is a production figure, so neither the size nor the outline of the device comes from Illinois law.
Can I keep using an embosser I already own?
Not as your only device. Because 225 ILCS 325/14 requires a reproducible seal, a bare embosser does not satisfy the rule on its own. Your reproducible impression has to come from an inked stamp or a computer generated seal.
Does the signature have to be handwritten?
The item beside the seal is described as your written signature, and 225 ILCS 325/14 also permits a computer generated signature. Either way, it sits adjacent to the seal together with the two dates.
Does Illinois want the signature written across the seal?
The cited provisions place the signature adjacent to the seal. Nothing in the facts checked for this page calls for signing across the impression.
What if my license lapses in the middle of a project?
The cited rules do not address seal use after a lapse. Licenses run to November 30 of odd-numbered years, so renew before that date to keep the expiration entry beside your seal current.
Start your order in our Illinois engineer stamps and seals collection with your name and license number exactly as licensed.
