3 January 2013 - 10p orange Machin definitive from counter sheets, with iridescent overprint.
The 10p counter sheet was reprinted on 09/02/18 by ISP Walsall, and was distributed by Royal Mail Tallents House on 23/05/18. Phosphor glows yellow under an ultra-violet lamp. By the time that was distributed, a second printing had already taken place.
The second Walsall reprint was 08/05/18: this has blue phosphor with yellow fluorescence to the transparent iridescent security ink.
SG U2923 as used for previous years
Cylinder blocks of 6
Date blocks of 8 - 08/05/18