Carter took over the top job temporarily when sales and marketing director Gordon Steele left at the beginning of this year. He was previously commercial marketing director.
Steele led the Post Office network through a series of changes including expansion into selling financial, telecoms and electrical products.
Hockey-Morley began his career at Unilever and moved on to London Electricity before joining Abbey in 1993.
He has held a variety of marketing roles at Abbey, including leading the retail bank and the mortgage and business banking arm. His current role is marketing director for its insurance and asset management division.
He will join the Post Office at the end of October to manage all of its marketing activity, according to Post Office managing director Alan Cook.
The Post Office's next move has long been predicted to be into broadband provision, and in July it was reported by Marketing to have started talks with Cable & Wireless to acquire its Bulldog brand. C&W had previously decided to stop Bulldog operating as a consumer brand and turn it into a wholesale provider.
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