19 May 2011 / December 2011

The Birds 4 set has 6 designs. The labels can be obtained with 5 different service indicators: 1st class & 1st class Large up to 100gr, Europe up to 20gr, Worldwide up to 10gr and 20gr, singly or in strips of up to 5 of the same value or various values. An additional 40g Worldwide option was made available from October at one London office using the basic Machin stamp, and the upgrade then rolled out nationwide over the next 2 months. Some of offices were still using Birds 3 and Birds 4 stock.

Set of 6 designs, 6 x 40g worldwide in a strip of 5 + 1.