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Is it necessary for a registered electrical contractor to inform the Electrical and Mechanical Services Department of any change in the registered particulars?

Electrical and Mechanical Services Department

Where any of the following particulars change after the registration of an electrical contractor, the contractor shall notify the Electrical and Mechanical Services Department (EMSD) within 2 weeks:

Changed particularsProcedures

The name under which the electrical contractor does business

  • If the Business Registration (BR) number remains unchanged: apply for replacement of the registration certificate (Note 1)
  • If the BR number is changed: New application for registration, please click here for details

Address of principal place of business

Apply for replacement of the registration certificate (Note 1)

Address of branch office

Apply for additional copy of the registration certificate (Note 2)

Correspondence address

Written notification to be provided by a person authorised by the registered electrical contractor (Note 3)

Telephone number

The partners in the case of a contractor registered as a partnership

Registered electrical workers employed by the contractor

The persons who are authorized to make an endorsement

Complete and submit the Form ER42 - Revising the Authorised Persons of the Registered Electrical Contractors (PDF) (Note 3)

Note 1:
Note 2:
  • Complete Form 2A – Details of Branch Offices of Registered Electrical Contractors(EMSD/LE/33, PDF), and return it to EMSD  Registration and Permit Office in person or by post. Submission can also be done online (Password and personal digital certificate are required).
  • When submitting the application, please also provide -
    • The copy of the certificate of registration;
    • Copy of the revised Branch Registration Certificate and relevant documents;
    • Application fee of $340. Cash is only accepted for application made in person. Cheques, Drafts and Cashier Orders should be made payable to the “The Government of the Hong Kong Special Administrative Region” and crossed.
Note 3:

Please prepare the required document by a person authorised by the contractor, and send it to the EMSD  Registration and Permit Office in person or by post. If the document is sent by post, EMSD will not acknowledge receipt of the notification. If necessary, please call 1823 to check 14 days after the date of posting.

EMSD Registration and Permit Office
Address : G/F, EMSD Headquarters, 3 Kai Shing Street, Kowloon Bay
Office hours:

  • Monday to Friday 9:00 am to 5:15 pm (open during lunch hours), Saturday, Sunday and Public Holidays closed
  • Saturday 8:30am to 12:30pm (drop-in box located at G/F lobby only)


In case of inclement weather or service adjustments due to special circumstances, the opening hours may be changed. Please refer to the departmental website and the latest press releases.

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Last update: 3 May 2022
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