BT was founded in August 31, 1916 by Henry Hellesen. Its first logo consisted of the "B.T." wordmark which uses the typeface which has its inspiration of Latin American stamps.
On August 31, 1926, in order to celebrate its 10th birthday, the logo was straightly modified with the emblem being remodified as well as the "B.T." wordmark becoming thinner.
In the 1940s, the whole logo turned red.
Starting in 1967, the emblem was removed from the logo by leaving it only with the "B.T." wordmark.
The final update of the 1916 logo came into force in 1994 by showing the logo making the dots turn into squared dots instead of rounded dots, and finally on 29 March 2012, this logo was discontinued after 95 years of usage.
On June 6, 2018, BT introduced back its classic 1994 logo with some minor changes. This logo was unveiled along with major revamp of its website.