Launching the initiative at Welshpool during the Prince's visit to Wales, M&S said it will promote the scheme in-store from July 4, with the Prince's feathers on packs of lamb.
Images released showed the original date '8th April 2005' printed on the reverse under the prince's feathers. A Mint spokesman said: 'The presses were due to run but we're now having to switch the date.'
The English bone china pieces, available in white or blue, have on them entwined letter Cs ( for Charles and Camilla ( surmounted by the Prince's Feathers of the Heir Apparent.