Laws forcing banks to widen account access could be introduced if uptake is not improved, the government has said.
Strict identity rules can bar account access to many
An estimated 1.9 million UK households - one in twelve - do not have access to a bank account.
The pre-Budget report is expected to set targets for uptake and may create a fund to tackle financial exclusion.
The government may also relax rules on identity - brought in to address money laundering concerns - which can make it hard for people to open accounts.
Stephen Timms, financial secretary to the Treasury, said legislation could be used as a "backstop" if the banks failed to act.
Mr Timms told BBC 1's Politics Show: "I'm pretty confident that we will be able to draw up a target that the banks and we can work jointly to achieve.
"Legislation is always a possibility. I don't think we are going to need it, but if we did, then that possibility would always be there."