Q: Does the Code of Practice on the Hong Kong ID Card Number and other personal identifiers ("the Code") permit a data user who has a valid paragraph 2.3 reason for collecting an ID card number, and who collects the number by means of collecting a copy of the card pursuant to paragraph 3.2.2.3, to retain the copy itself as the data user's permanent record of the ID Card number?
A: The Code does not in itself purport to prohibit a data user from retaining an ID copy at any time after such collection.
The following requirements of the Personal Data Privacy Ordinance ("the Ordinance") are relevant to the retention of personal data in general:
"A data user shall erase personal data held by the data user where the data are no longer required for the purpose (including any directly related purpose) for which the data were used unless-
(a) any such erasure is prohibited under any law; or
(b) it is in the public interest (including historic interest) for the data not to be erased."; and
Data Protection Principle ("DPP") 2(2) in Schedule 1:
"Personal data shall not be kept longer than is necessary for the fulfillment of the purpose (including any directly related purpose) for which the data are or are to be used."
Applying these requirements to an ID copy collected pursuant to paragraph 3.2.2.3 of the new Code, it follows that where the purpose for which the ID copy (and the personal data contained therein) were used consisted either in:
(i) the verification of an ID number collected separately by the data user; or
(ii) the collection of the ID number from such copy, which number has subsequently been transferred and recorded elsewhere by the data user.
then the purpose for which the ID copy was used was fulfilled upon the completion of the verification or transfer process, as the case may be. Unless there are other valid purposes for the collection of the ID copy (as given in the other provision of paragraph 3.2 of the new Code) which purposes have not been fulfilled according to DPP 2(2), the personal data on the ID card copy should be retained no further.
Apart from the above situations, however, it is also possible to have a different situation where the ID card copy is also collected pursuant to paragraph 3.2.2.3, but the number is not subsequently transferred elsewhere, hence the ID card copy remains the only record of the ID number held by the data user. In this case, we are inclined to take the view that the ID card copy as a whole has not outlived its original use, hence it may be retained as the record of the ID number for just so long as such number may be retained by the data user.