The five-day conference and exhibition will take place from 27 April-1 May 2014 and again from 25-30 April 2015, with more than 2,000 delegates expected to attend both events.
The 2014 and 2015 Annual Conferences are estimated to contribute £3.2m in economic benefit to the local economy through business tourism.
Tony Kearns, senior deputy general secretary for the CWU, said: "Our annual conferences are motion based and provide the opportunity to discuss current issues.
"We are thrilled to be returning to Bournemouth; the CWU Annual Conference has been held at the Bournemouth International Centre for many years as the location is well-received by delegates and we have built a great working relationship with the venue."
The CWU Annual Conference returns to the BIC having been held at the venue yearly since 2009.