TR-1: Standard form for notification of major holdings

1. Issuer Details

ISIN

GB0004866223

Issuer Name

KELLER GROUP PLC

UK or Non-UK Issuer

UK

2. Reason for Notification

An event changing the breakdown of voting rights

3. Details of person subject to the notification obligation

Name

Dimensional Fund Advisors LP

City of registered office (if applicable)

Austin

Country of registered office (if applicable)

USA

4. Details of the shareholder

     Name                         City of registered      Country of registered
                             office                  office

  Funds and accounts managed
by Dimensional Fund Advisors
LP and/or its subsidiary
undertakings

5. Date on which the threshold was crossed or reached

07-May-2026

6. Date on which Issuer notified

11-May-2026

7. Total positions of person(s) subject to the notification obligation

                     % of          % of voting
                voting rights rights through        Total of         Total
   .            attached to   financial        both in % (8.A + number of voting
                shares (total instruments      8.B)             rights held in
                of 8.A)       (total of 8.B 1                   issuer
                              + 8.B 2)

  Resulting
situation on
the date on       4.996175      0.000000         4.996175         3,495,662
which threshold
was crossed or
reached

  Position of
previous          5.003855      0.000000         5.003855
notification
(if applicable)

8. Notified details of the resulting situation on the date on which the threshold was crossed or reached

8A. Voting rights attached to shares

     Class/Type      Number of       Number of       % of direct      % of
of shares ISIN  direct voting   indirect voting voting rights    indirect voting
code(if         rights (DTR5.1) rights          (DTR5.1)         rights
possible)                       (DTR5.2.1)                       (DTR5.2.1)

  GB0004866223                    3,495,662                        4.996175

     Sub Total       3,495,662                       4.996175
8.A

8B1. Financial Instruments according to (DTR5.3.1R.(1) (a))

                                                   Number of
     Type of                                  voting rights that       % of
financial      Expiration Exercise/conversion may be acquired if  voting rights
instrument     date       period              the instrument is
                                              exercised/converted

     Sub Total
8.B1

8B2. Financial Instruments with similar economic effect according to (DTR5.3.1R.(1) (b))

     Type of                                                 Number      % of
financial    Expiration Exercise/conversion Physical or of voting   voting
instrument   date       period              cash        rights      rights
                                            settlement

     Sub
Total 8.B2

9. Information in relation to the person subject to the notification obligation

2. Full chain of controlled undertakings through which the voting rights and/or the financial instruments are effectively held starting with the ultimate controlling natural person or legal entities (please add additional rows as necessary)

                                                     % of voting
                                    % of voting rights through        Total of
     Ultimate      Name of     rights if it     financial        both if it
controlling   controlled       equals or is     instruments if   equals or is
person        undertaking      higher than the  it equals or is  higher than the
                               notifiable       higher than the  notifiable
                               threshold        notifiable       threshold
                                                threshold

                i) Dimensional
              Fund Advisors
              Ltd., (ii) DFA
              Australia
              Limited (iii)
              Dimensional
  Dimensional Ireland LimitedHoldings Inc. (iv) Dimensional
              Fund Advisors
              Canada ULC (v)
              Dimensional Fund
              Advisors Pte.
              Ltd. and (vi)
              Dimensional Fund
              Advisors LP

10. In case of proxy voting

Name of the proxy holder

The number and % of voting rights held

The date until which the voting rights will be held

11. Additional Information

The ordinary shares are held in segregated accounts and funds (together, the “Accounts”) managed on a discretionary basis by Dimensional Fund Advisors LP ("Dimensional") and its subsidiary undertakings i) Dimensional Fund Advisors Ltd., (ii) DFA Australia Limited (iii) Dimensional Ireland Limited (iv) Dimensional Fund Advisors Canada ULC (v) Dimensional Fund Advisors Pte. Ltd. and (vi) Dimensional Fund Advisors LP.

As at 7 May 2026, Dimensional also had investment management discretion over an additional 10,061 shares where the voting rights are not controlled by Dimensional or its subsidiary undertakings.

Dimensional is controlled by its general partner, Dimensional Holdings Inc.

Dimensional, on behalf of itself and its subsidiary undertakings, expressly disclaims beneficial ownership of the shares held in the Accounts.

12. Date of Completion

11-May-2026

13. Place Of Completion

Paris

CONTACT:

Enquiries:

Jamie Dearsley

Assistant Company Secretary

+44 7824 584 151

Keller Group plc

LEI Number:         549300QO4MBL43UHSN10