HC Deb 26 April 1950 vol 474 c99W
76. Wing-Commander Bullus

asked the Postmaster-General why certain letters posted in the London area on 11th April, 1950, were postmarked 28th April, 1950.

Mr. Ness Edwards

A mechanical mistake occurred in the operation of a postage meter franking machine by a firm; the letters referred to were franked and posted by a private firm. I understand that their error was due to a mistake by one of their employees.