1897 Mengtsz (15 Jun) to Great Northern Telegraph Co., Shanghai, applied with Customs Mengtzo type C cds in black. In combination with
1897 Mengtsz (15 Jun) to Great Northern Telegraph Co., Shanghai, applied with Customs Mengtzo type C cds in black. In combination with Navigation and Commerce issue 25c in pair, tied by Laokay (21 Jun) cds. Transit Yen-Bai (23 Jun), Hanoi (26 Jun), Haiphong (27 Jun), Hong Kong (7 Jul). Arrived Shanghai BPO (12 Jul). Customs Post was only available for internal mails so no Chinese franking was required.1897.6.15 蒙自寄上海大北電報公司，背面鈐蒙自海關C型黑色日戳。正面加貼航海及商貿神像25生丁雙連，銷老街6.21日戳。6.23經安沛，6.26經河內，6.17經海防，7.7經香港。7.12抵上海英局。當時海關郵政僅供關員使用，故鈐蒙自海關日戳後只需貼印支票，
