To ensure that mail in transport does not present danger during its transmission, prohibited or dangerous articles must never be sent in the Post (both air and surface).
According to the international postal regulations, lithium batteries as one of the dangerous goods, are prohibited from transmission through the postal channel. To step up with the postal security so as to ensure that mail in transport does not present danger during transmission, the restriction on lithium batteries is extended to cover surface mail with effective from 19 October 2015.
Lithium batteries are prohibited from sending through the Post irrespective of any postal services and mode of transmission. Lithium batteries if detected during mail processing, will be returned and the sender will not be entitled to any postage refund. The sender may also be liable to prosecution. Details on the prohibitions, customs declaration and the posting requirement of the overseas destination are given in Section 6.3, 9.5 and the Appendix of the Post Office Guide.