The nation’s largest banks are testing how much their customers are willing to pay for checking-account services that used to be free.

Bank of America Corp. and J.P. Morgan Chase & Co., the two biggest banks as measured by assets, have begun trying new fees in pilot tests from Hayward, Wis., to Newnan, Ga.

They include an account that charges a $3 monthly fee for debit cards. Another account designed for electronic-only banking charges customers a $12 monthly fee if customers go to a teller for assistance. In the test programs, some bare-bones checking accounts also now carry base fees ranging from $6 to $9 a month.

The new fees, which are limited to accounts for new and prospective customers in the pilot programs, can typically be waived if customers meet certain criteria.

The pilot testing is the latest indication of the push to boost fees as banks scramble to make up billions of dollars of revenue expected to be lost from new federal restrictions on debit cards.

The Federal Reserve in December proposed capping the amount banks can charge merchants for debit transactions at seven to 12 cents, from an average rate of 44 cents. The Fed’s proposal could reduce the revenue banks make from such fees, known as interchange, by 57% to $9.8 billion, according to CardHub.com.

Read more: The Wall Street Journal