HSBC Bank USA - the North American subsidiary of the British banking group - has been struggling to restore data and update account balances following technical problems with its core banking platform.
HSBC Bank USA has been trying to restore services after its core banking platform crashed last Sunday.
In a statement posted on its Web site the same day, the bank says most of the impacted systems are now "fully functional and our teams continue to work through any remaining issues".
But according press reports, some customer accounts were still not up to date yesterday, due to the volume of transactions the bank handles each day. This has left many customers unsure of the funds actually available in their accounts.
A notice on the HSBC Bank USA Web site says funds from cheques deposited August 16-19 will be posted to accounts and made available by today.
HSBC Bank USA spokesperson Linda Recupero told reporters that the bank is still "working through the remaining recovery efforts".