ASP Isotopes (ASPI) delays Q1 2026 10-Q; files notice under Rule 12b-25

Rhea-AI Filing Summary

ASP Isotopes Inc. notified the SEC it cannot timely file its Form 10-Q for the period ended March 31, 2026. The company states the delay stems from obtaining and compiling required information and says it will file the Form 10-Q no later than the fifth calendar day following the prescribed due date.

The notification was signed by Heather Kiessling, Chief Financial Officer, on May 15, 2026.

Key Figures

Form period end: March 31, 2026 Cure period: fifth calendar day SEC file number: 001-41555 +3 more

6 metrics

Form period end March 31, 2026 quarter end for the delayed Form 10-Q

Cure period fifth calendar day deadline to file under Rule 12b-25 for quarterly reports

SEC file number 001-41555 registrant's SEC file number on the notice

CUSIP 00218A105 security identifier shown on the notice

Contact phone (214) 432-8219 telephone number for Heather Kiessling provided on the form

Signature date May 15, 2026 date the CFO signed the Form 12b-25

Key Terms

Rule 12b-25, Form 10-Q, Form 12b-25

3 terms

Rule 12b-25 regulatory

"The Registrant will file its Form 10-Q no later than the fifth calendar day following the prescribed due date"

Rule 12b-25 is an SEC filing provision that lets a company notify regulators and the public that it cannot file a required periodic report (like a quarterly or annual report) on time and explains the reason for the delay. For investors, the notice is a formal heads-up that financial information will arrive late—similar to a company calling to say it will be late turning in homework—so it signals increased uncertainty and may affect trading and risk assessments until the filing is available.

Form 10-Q financial

"The Registrant could not complete the filing of its Quarterly Report on Form 10-Q for the quarter ended March 31, 2026"

A Form 10-Q is a detailed report that publicly traded companies are required to file with regulators three times a year, providing an update on their financial health and business activities. It is important for investors because it offers timely insights into a company's performance, helping them make informed decisions about buying or selling stocks. Think of it as a regular check-up report that shows how well a company is doing.

Form 12b-25 regulatory

"NOTIFICATION OF LATE FILING FORM 12b-25"

Form 12b-25 is a notice a publicly traded company files with the U.S. Securities and Exchange Commission when it cannot deliver a required periodic report (like a quarterly or annual financial report) on time. It explains the reason for the delay and gives the company a short, temporary window to finish the report without being marked as delinquent; investors watch it because late filings can signal accounting, operational, or control issues that may affect a company’s reliability and stock risk, much like a missed homework deadline can raise concerns about a student’s preparedness.

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	FORM 12b-25	SEC FILE NUMBER
		001-41555
		CUSIP NUMBER
	NOTIFICATION OF LATE FILING	00218A105

(Check one):

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Form 10-K

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Form 20-F

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Form 11-K

☒

Form 10-Q

☐

Form 10-D

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Form N-CEN

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Form N-CSR

For Period Ended: March 31, 2026

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Transition Report on Form 10-K

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Transition Report on Form 20-F

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Transition Report on Form 11-K

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Transition Report on Form 10-Q

For the Transition Period Ended: __________________________________________

Nothing in this form shall be construed to imply that the Commission has verified any information contained herein.

If the notification relates to a portion of the filing checked above, identify the Item(s) to which the notification relates:

PART I - REGISTRANT INFORMATION

ASP Isotopes Inc.

Full Name of Registrant

Former Name if Applicable

2200 Ross Avenue, Suite 4575E

Address of Principal Executive Office (Street and Number)

Dallas, Texas 75201

City, State and Zip Code

PART II - RULES 12b-25(b) AND (c)

If the subject report could not be filed without unreasonable effort or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the following should be completed. (Check box if appropriate)

☒	(a)	The reason described in reasonable detail in Part III of this form could not be eliminated without unreasonable effort or expense;
	(b)	The subject annual report, semi-annual report, transition report on Form 10-K, Form 20-F, Form 11-K, Form N-CEN or Form N-CSR, or portion thereof, will be filed on or before the fifteenth calendar day following the prescribed due date; or the subject quarterly report or transition report on Form 10-Q or subject distribution report on Form 10-D, or portion thereof, will be filed on or before the fifth calendar day following the prescribed due date; and
	(c)	The accountant’s statement or other exhibit required by Rule 12b-25(c) has been attached if applicable.

PART III - NARRATIVE

State below in reasonable detail the reasons why Forms 10-K, 20-F, 11-K, 10-Q, 10-D, N-CEN, N-CSR, or the transition report or portion thereof, could not be filed within the prescribed time period.

(Attach extra Sheets if Needed)

The Registrant could not complete the filing of its Quarterly Report on Form 10-Q for the quarter ended March 31, 2026 due to a delay in obtaining and compiling information required to be included in its Form 10-Q, which delay could not be eliminated by the Registrant without unreasonable effort and expense. In accordance with Rule 12b-25 promulgated under the Securities Exchange Act of 1934, the Registrant will file its Form 10-Q no later than the fifth calendar day following the prescribed due date.

PART IV - OTHER INFORMATION

(1)Name and telephone number of person to contact in regard to this notification

Heather Kiessling		(214)		432-8219
(Name)		(Area Code)		(Telephone Number)

(2)Have all other periodic reports required under Section 13 or 15(d) of the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of 1940 during the preceding 12 months or for such shorter period that the registrant was required to file such report(s) been filed? If answer is no, identify report(s). Yes ☒ No ☐

(3)Is it anticipated that any significant change in results of operations from the corresponding period for the last fiscal year will be reflected by the earnings statements to be included in the subject report or portion thereof? Yes ☐ No ☒

If so, attach an explanation of the anticipated change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be made.

2

ASP Isotopes Inc.

(Name of Registrant as Specified in Charter)

has caused this notification to be signed on its behalf by the undersigned hereunto duly authorized.

Date: May 15, 2026	By:	/s/ Heather Kiessling
		Heather Kiessling
		Chief Financial Officer

3

FAQ

Why did ASP Isotopes (ASPI) file a Form 12b-25 for its March 31, 2026 10-Q?

The company cites a delay in obtaining and compiling required information needed for the Form 10-Q. It says the delay "could not be eliminated without unreasonable effort and expense" and that this was the reason for the notification.

When will ASPI file the delayed Form 10-Q for the quarter ended March 31, 2026?

ASPI states it will file the Form 10-Q no later than the fifth calendar day following the prescribed due date. The notification explicitly ties the filing timetable to Rule 12b-25's permitted cure period.

Who signed the late-filing notification for ASP Isotopes (ASPI)?

The Form 12b-25 was signed by Heather Kiessling, Chief Financial Officer, on May 15, 2026. A contact phone number, (214) 432-8219, is provided for follow-up.

Does the Form 12b-25 indicate changes to ASPI's prior filings or results?

No. The notification only states the Form 10-Q could not be completed on time due to compilation delays. It does not report any anticipated material change in results for the quarter or identify missing prior filings.