Trinseo (TSE) CTO reports 7,707-share tax withholding after RSU vesting

Rhea-AI Filing Summary

Trinseo PLC senior executive Hendriks Han, the company’s SVP and Chief Technology Officer, reported a tax-withholding share disposition related to vesting restricted stock units. On this Form 4, 7,707 Ordinary Shares were withheld at $0.23 per share to cover taxes. After this withholding, Han directly holds 73,362 Ordinary Shares.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Hendriks Han

Role SVP, CHIEF TECHNOLOGY OFFICER

Type	Security	Shares	Price	Value
Tax Withholding	Ordinary Shares	7,707	$0.23	$2K

Holdings After Transaction: Ordinary Shares — 73,362 shares (Direct)

Footnotes (1)

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Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Hendriks Han

(Last) (First) (Middle)

C/O TRINSEO PLC

440 EAST SWEDESFORD ROAD, SUITE 301

(Street)

WAYNE PA 19087

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Trinseo PLC [ TSE ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	SVP, CHIEF TECHNOLOGY OFFICER

3. Date of Earliest Transaction (Month/Day/Year)
02/27/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Ordinary Shares	02/27/2026		F		7,707(1)	D	$0.23	73,362	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Shares withheld by the Company to pay taxes due following the vesting of restricted stock units.

	/s/ Angelo Chaclas, Attorney-in-Fact	03/03/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did Trinseo (TSE) report for Hendriks Han?

Trinseo reported a Form 4 for SVP and Chief Technology Officer Hendriks Han. The filing shows 7,707 Ordinary Shares were disposed of through tax withholding tied to vesting restricted stock units, rather than an open-market sale, at a price of $0.23 per share.

How many Trinseo (TSE) shares were withheld for taxes in this Form 4?

The Form 4 shows 7,707 Trinseo Ordinary Shares were withheld for taxes. These shares covered tax obligations arising when restricted stock units vested, using a transaction coded “F” at a reported price of $0.23 per share, according to the filing’s footnote.

What does the Form 4 code "F" mean for Trinseo (TSE) insider Hendriks Han?

Code “F” on this Form 4 indicates shares were used to pay tax liabilities. For Hendriks Han, 7,707 Ordinary Shares were withheld by the company following the vesting of restricted stock units, rather than being sold in the open market for discretionary purposes.

How many Trinseo (TSE) shares does Hendriks Han own after this transaction?

After the tax-withholding disposition, Hendriks Han directly owns 73,362 Trinseo Ordinary Shares. This figure reflects his holdings following the withholding of 7,707 shares to satisfy taxes due upon vesting of restricted stock units, as detailed in the Form 4 filing.

Was the Trinseo (TSE) insider transaction an open-market sale of shares?

No, this transaction was not an open-market sale. The Form 4 and its footnote explain that 7,707 shares were withheld by Trinseo to pay taxes due after restricted stock units vested, a routine administrative disposition coded as a tax-withholding event.

What price per share is reported in the Trinseo (TSE) Form 4 for this transaction?

The Form 4 reports a transaction price of $0.23 per Trinseo Ordinary Share. This price is associated with the 7,707 shares withheld to satisfy tax obligations on vesting restricted stock units and does not represent a voluntary open-market sale by the executive.