Claire Walker and Hannah Essex have been co-directors of comms at education charity Teach First since 2015. Walker joined the organisation in 2014 and Essex in 2010, both having worked at various other charities previously.
They will join BCC in September and become part of its leadership team, taking over from interim incumbent Ian Hagg and leading a dozen-strong team.
Walker will work Monday to Wednesday and Essex from Wednesday to Friday.
The pair will lead BCC's policy position and lobbying, including campaigns around eradicating mobile "not-spots" (ie areas lacking signal), fixing the fundamentals of the UK's domestic infrastructure, and Brexit.
Walker and Essex submitted a joint application for the job, of which BCC director-general Adam Marshall said: "BCC has a firm upfront commitment to considering all applications, including those who seek to work flexibly... their application was considered in exactly the same way as that of the other candidates."
"We were very satisfied that they are able to manage the practical and logistical aspects of sharing a senior management role within our business," he went on to say.
The duo said in a statement: "We are thrilled to be joining the British Chambers of Commerce as such a critical time for British business. We want to ensure the UK thrives - now and post-Brexit.
"We know that when business succeeds, communities and families succeed, too. We are excited at the opportunity to represent the Chambers’ diverse membership to ensure they have the conditions they need to achieve."
Marshall also commented: "This is a critical time for the UK business community, and in Claire and Hannah we have found two dynamic individuals who together will be able to campaign for Chamber business communities, and take our agenda to an even higher level."