An Illinois geologist seal is a 1 3/4 inch circle of concentric rings, with LICENSED PROFESSIONAL GEOLOGIST across the upper band, ILLINOIS across the lower band, and your name and license number inside the inner circle. Each sealed record also carries your full name, signature, license number and license expiration date. This page covers the face, the device, the record, renewal timing and ordering.
Engineer Seal Stamps compliance desk. Checked against 68 Ill. Adm. Code 1252.APPENDIX A(a). Sources read September 2026.
| Requirement | What the rule says | Source |
|---|---|---|
| Diameter and outline | A circle measuring exactly 1 3/4 inches. | 68 Ill. Adm. Code 1252.APPENDIX A(a) |
| Top band | The words LICENSED PROFESSIONAL GEOLOGIST, all capitals, set between the two rings. | 68 Ill. Adm. Code 1252.APPENDIX A(a) |
| Bottom band | ILLINOIS, all capitals, also between the rings. | 68 Ill. Adm. Code 1252.APPENDIX A(a) |
| Inner circle | Your name and your individual license number. | 68 Ill. Adm. Code 1252.APPENDIX A(a) |
| Device | A seal or a rubber stamp, bought at your own cost. | 68 Ill. Adm. Code 1252.APPENDIX A(a) |
| On the record | Your full name, signature, license number and license expiration date, together with the impression. | 225 ILCS 745/60(b) |
| Documents covered | Broad, and expressly taking in work that most states leave out. | 225 ILCS 745/60(b), (c), (d), (e) |
| Electronic sealing | Neither the Act's seal section nor Appendix A mentions it, and Part 1252 has no provision on it. | 225 ILCS 745/60 |
| License term | Licenses run out on March 31 in odd-numbered years, and renewal is open during the month before. | 68 Ill. Adm. Code 1252.70(a) |
| Sealing after a lapse | Not addressed. | Not addressed in the cited rules |
What appears on the face of an Illinois geologist seal?
Two legends in the band between the concentric circles and two personal details inside. LICENSED PROFESSIONAL GEOLOGIST runs across the top band in capitals, ILLINOIS runs across the bottom band in capitals, and your name and individual license number sit within the inner circle.
The lower band carries the one word ILLINOIS. A template that fills that band with State of Illinois adds words the rule does not list. Both legends are specified in capitals, so lowercase or mixed-case lettering on either band departs from Appendix A(a).
Our article on the Illinois licensed geologist seal looks at the seal's role in practice.
What size is the Illinois geologist seal?
Exactly 1 3/4 inches in diameter, as a circle. Appendix A(a) states a single figure rather than a range or a minimum, so the seal is ordered at that size and no other.
A fixed diameter has a practical effect on lettering. The two capital legends share the band between the rings, and your name and license number share the inner circle, so a long name is set smaller to fit rather than pushing the diameter up. Our piece on the Illinois geologist stamp covers the product side.
Can you use a rubber stamp, or must it be a seal?
Either one. Appendix A(a) allows a seal or a rubber stamp. Whichever you choose still has to produce the 1 3/4 inch concentric design with both legends and both personal details in their assigned places.
For work that goes out on paper and gets copied, test the impression from whichever device you pick on a copy before you rely on it. Our guide to acquiring an Illinois geologist seal covers buying one.
What else must appear on a sealed Illinois record?
Four items along with the impression: your full name, your signature, your license number, and the date your license expires. Section 60(b) of the Professional Geologist Licensing Act puts all of them, together with the seal impression, on the record.
The date named in section 60(b) is your license expiration date, which is a different thing from a signing date. It changes with each renewal cycle while the seal itself stays the same, so put a labeled space for it in your title block or report cover and fill it in every time.
Which Illinois documents fall under the sealing duty?
A wide range. Section 60 of the Act, in subsections (b) through (e), sets a sealing duty that is broad and expressly reaches work that most states exempt from sealing.
If you have practiced elsewhere, do not carry over exemptions from another state's rules. Read subsections (b), (c), (d) and (e) together before deciding that a particular record can go out unsealed in Illinois, because the Illinois duty was written wider than the norm.
Does Illinois allow electronic geologist seals?
The rules are silent. Section 60 of the Act and Appendix A both say nothing about sealing or signing electronically, and no provision in Part 1252 of the Illinois Administrative Code addresses electronic sealing either.
That silence cuts both ways. The rules do not set up an electronic process and they do not forbid one. They describe a seal or rubber stamp and an impression on the record, and stop there.
How does license renewal affect the seal and your records?
The seal itself is unaffected, because nothing on its face is a date. Licenses expire on March 31 in odd-numbered years and can be renewed in the month before, so what changes at renewal is the expiration date you write on each record.
Update your title block template as soon as a renewal goes through, so the new expiration date appears on the next record you seal. Use of the seal after a license lapses is not addressed in the cited rules. Our article on Illinois geologist certification covers the license side.
What should you send with an Illinois geologist seal order?
Your name as it should appear, your individual license number, and confirmation that the seal is a 1 3/4 inch circle with LICENSED PROFESSIONAL GEOLOGIST in the top band and ILLINOIS in the bottom band, both in capitals.
- Your name, for the inner circle
- Your individual license number, also for the inner circle
- Diameter: 1 3/4 inches
- Device: seal or rubber stamp
Our note on getting an Illinois geologist stamp made covers the ordering steps.
How do you check the seal before its first use?
Measure a test impression, which should come to 1 3/4 inches across. Then confirm both legends are in capitals in the right bands, that the bottom band reads ILLINOIS alone, and that your name and license number sit inside the inner circle.
Next, mock up a full record. Stamp a sample title block or report cover and fill in your full name, signature, license number and license expiration date on the same sheet, so you can see all five elements together before a real document goes out.
Every other jurisdiction is compared in our geologist seal rules for all 54 U.S. jurisdictions, with the citation for each.
Frequently asked questions
Does the license expiration date go inside the seal?
No. Appendix A(a) lists the two legends, your name and your license number for the face. The expiration date belongs elsewhere on the record, under section 60(b).
Who pays for the seal?
You do. Appendix A(a) makes the seal or rubber stamp a cost that each licensee bears personally.
Is a 2 inch or 1 1/2 inch stamp close enough?
No. Appendix A(a) fixes the diameter at 1 3/4 inches, so a stock size above or below that figure does not match the rule.
Does my name have to be in capitals?
The capitals requirement in Appendix A(a) attaches to the two legends. The rule places your name and license number in the inner circle without stating a letter case for them.
What expiration date do I write right after renewing?
The new one. Licenses expire on March 31 of odd-numbered years, so once a renewal goes through, the date on your records moves to March 31 of the next odd-numbered year.
With your license number in hand, pick a 1 3/4 inch seal or rubber stamp from our Illinois stamps and seals collection.
