'BACH' stands for -

Bangladesh Automated Clearing House (BACH):
BACH is the first-ever electronic clearing house of Bangladesh, has two components -
the Automated Cheque Processing System (ACPS) and the Electronic Funds Transfer (EFT).
Both the systems operate in batch processing mode- transactions received from the banks during the day are processed at a pre-fixed time and settled through a single multilateral netting figure on each individual bank's respective books maintained with the Bangladesh Bank.
A state-of-the-art Data Center (DC) and a Disaster Recovery Site (DRS) have been established comprising of most modern software and hardware for dealing with the operations of BACH.
A Virtual Private Network (VPN) has been created between the participating commercial banks and Data Center (DC) & Disaster Recovery Site (DRS) for communicating necessary information related to BACH.
Digital Certificate has been formulated for the first time in Bangladesh for secured data communication.

Source: Bangladesh Bank Website