The contract, which forms part of HSBC's annual UK marcomms spend, has moved to St Ives, which triumphed in the tender for the first UK-wide HSBC marcomms BPO contract.
HSBC previously contracted its UK marcomms print spend directly across several different print suppliers, of which Communisis was one.
In a statement to the London Stock Exchange (LSE), Communisis said "that it expects that its existing contract with HSBC for direct mail services will be awarded to another supplier".
It added: "No termination notice has been received by the Company but a statement from HSBC to that effect has been quoted in a trade publication. The contract is terminable on one month's notice.
"Communisis' separate and significant contracts with HSBC for transactional (statement and billing) and cheque printing are unaffected.
"The current annual sales value of the direct mail contract is approximately £7m. The company expects that the loss of revenue from this contract, were it to be terminated in the current financial year, would largely be limited to the fourth quarter."
Communisis said that management expectations for overall group results for both 2011 and 2012 remained unchanged despite the contract loss.