3rd Supplementary Agreement of the Second Train Inspection Shop and Relevant Maintenance Shops at Zuoying Depot of THSRC

1.Name and nature of the underlying asset (e.g., land located at Sublot XX, Lot XX, North District, Taichung City):
   3rd Supplementary Agreement of Construction Works for the Second Train Inspection Shop and
   Relevant Maintenance Shops at Zuoying Depot of Taiwan High Speed Rail.
2.Date of occurrence of the event: 2026/03/18
3.Date of the board of directors resolution: 2026/03/18
4.Other approval date: Not applicable.
5.Transaction unit amount (e.g.XX square meters, equivalent to XX ping), unit price, and total transaction price:
   (1) Unit amount: Not applicable
   (2) Unit price: Not applicable
   (3) Total transaction price: The contract price is updated as 5,182,537 thousand NTD (Tax inclusive).
6.Trading counterparty and its relationship with the Company (if the trading counterparty is a natural person
    and furthermore is not a related party of the Company, the name of the trading counterparty is not required
    to be disclosed): FORMOSA BUILDERS, Inc., non-related party of  THSRC.
7.Where the trading counterparty is a related party, announcement shall also be made of the reason for choosing
    the related party as trading counterparty and the identity of the previous owner, its relationship with the Company 
    and the trading counterparty, and the previous date and monetary amount of transfer: Not applicable.
8.Where an owner of the underlying assets within the past five years has been a related party of the Company,   
   the announcement shall also include the date and price of acquisition and disposal by the related party, and its 
   relationship with the Company at the time of the transaction: Not applicable.
9.Projected gain (or loss) through disposal (not applicable for acquisition of assets; those with deferral should provide
    a table explaining recognition): Not applicable.
10.Terms of delivery or payment (including payment period and monetary amount), restrictive covenants in the contract, 
     and other important terms and conditions: Terms of delivery and payment: In accordance with the Contract; Restrictive
     clauses and other important covenants: None.
11.The manner of deciding on this transaction (such as invitation to tender, price comparison, or price negotiation),
     the reference basis for the decision on price, and the decision-making unit:
     The transaction price was determined through negotiation. The price reference was based on market price assessments
     conducted by THSRC in conjunction with the design and supervision units, and finalized through negotiations with the
     contractor. Decision-making Body: Board of Directors.
12.Name of the professional appraisal firm or company and its appraisal price: Not applicable.
13.Name of the professional appraiser: Not applicable.
14.Practice certificate number of the professional appraiser: Not applicable.
15.The appraisal report has a limited price, specific price, or special price: Not applicable.
16.An appraisal report has not yet been obtained: Not applicable.
17.Reason for an appraisal report not being obtained: Not applicable.
18.Reason for any significant discrepancy with the appraisal reports and opinion of the CPA: Not applicable.
19.Name of the CPA firm: Not applicable.
20.Name of the CPA: Not applicable.
21.Practice certificate number of the CPA: Not applicable.
22.Broker and broker's fee: Not applicable.
23.Concrete purpose or use of the acquisition or disposal: In accordance with the train maintenance capacity
     and parking demand, it is planned to build a second train inspection and maintenance shop at the Zuoying
     Depot to ensure the maintenance and parking capacity can meet the demand.
24.Any dissenting opinions of directors to the present transaction: None.
25.Whether the counterparty of the current transaction is a related party: No
26.Date of ratification by supervisors or approval by the audit committee: NA
27.The transaction is to acquire a real property or right-of-use asset from a related party: No
28.The price assessed in accordance with the Article 16 of the Regulations Governing the Acquisition
     and Disposal of Assets by Public Companies: Not applicable.
29.Where the above assessed price is lower than the transaction price, the price assessed in accordance
     with the Article 17 of the same regulations: Not applicable.
30.Date on which material information regarding the same event has been previously released: 2024/10/22
31.Any other matters that need to be specified: Approved by the 37th meeting of the 10th Board of Directors
     on March 18, 2026. The Board has authorized the Chairman to determine the dates of signing and taking
     effect, based on the consensus reached through negotiations between both contracting parties.