The Halifax hit back at claims that it was trying to ban less well off customers from using its branches.
The country's biggest savings bank and mortgage lender was responding to criticism of a pilot scheme aimed at encouraging those with basic Card Cash accounts to use cash machines, the telephone and the internet for transactions.
The scheme, which involves 20 branches in south-east London, is aimed at trimming queuing times for customers who need face-to-face service.
Consumer groups claimed that Halifax was treating Cash Card account holders as an unwanted nuisance and trying to shunt them aside in favour of the better off.
The Card Cash account is used by people who simply want to pay money into an account and take it out again, rather than those who want the range of services provided by a current account, such as an overdraft.
Although it has some features of a basic bank account, which are aimed at people on low incomes who would not normally have access to bank services, Halifax said it was not the same as people needed to be credit-scored to open one.
The group has written to holders of the accounts in the areas involved in the trial asking them to use the internet, telephone and ATMs to manage their finances.
It said if someone did use the counter service, they would be shown how to use the other technologies available in the branch. People who may have difficulty using these, such as the elderly or those with special needs, would be able to continue using the counter service as before.
Halifax spokesman Mark Hemingway said: "So far the results of the pilot project have been very encouraging.
"In the branches concerned, queuing times for counter service have been cut dramatically from 20 minutes to five minutes.
"It is not true to say that we are banning customers from using branches. We are pointing out that self-serve technology is there for those who want to use it."
Halifax will not decide whether to extend the policy to the rest of the country until the London pilot scheme ends in April next year.
Meanwhile, it emerged that Halifax has cut the rates paid on some of its savings accounts by up to twice as much as mortgages following last month's reduction in base rate.
The full quarter point cut has been passed on to borrowers but the savings rate applied to the children's Halifax Monthly Saver account has been slashed by half a point.
Halifax has also reduced the rate on its Liquid Gold account on balances of more than £500 by the full 0.25 per cent to just 0.7 per cent. A spokesman said: "Some rates haven't changed, some have changed by less than 0.25 per cent, some by 0.25 per cent and some by more than 0.25 per cent.
"The savings market is being rejigged."