This is an example of Jesselton GPO postmark that appeared in ebay in Nov 2009 last year. This particular cover was sold for £42. This is an official cachet which was added to post office communications from approximately in 1890s until the outset of world war II (1943). The postmark on top right shows a date of "4 Dec 1933" while the lower left postmark shows the BNB coat of arms in the centre and inscribed * General Post Office * Jesselton B.N.B *. There are only two recorded post office official seals in North Borneo; the Jesselton GPO and Sandakan PO.

Sandakan GPO Postmark (1941)

Another fine example of the post office postmark in North Borneo. The date on top right corner is not very clear but my guess is that it is "18 June 1941". Compared to the Jesselton GPO mark on top, this particular post office postmark has a lot more detail, bigger in size and has a narrower space between the innner and outer rings. Like the one on top, this is a stampless cover with the "OGS" imprint and "Official Paid" mark (30.08.1939 - 18.06.1941). It also bears a red triangle inscibed "Passed for Transmission | North Borneo | 7 ". Sold by a German auctioneer for €85 in 2006.

Sandakan GPO Red Postmark (1891)



Description
1891 (6 Apr.) OHMS envelope "On Money Order Business" to Germany, showing superb large double-ring "post office/Coat of Arms/sandakan" cachet alongside equally fine "sandakan" c.d.s. (Type D4), both in red, the reverse with Singapore (14.4) and Erfurt (9.5) c.d.s.; a rare and most unusual cover. Estimated price: $ 1000 - $1,200.
Note: North Borneo joined the U.P.U. on 1 January 1891. Under U.P.U. regulations letters on Post Office business were free of postage.