For the first time in years, banks are offering savings accounts that pay serious interest. But consumers aren’t doing much about it, a new survey finds.

Roughly one-fifth of Americans with savings accounts don’t know how much interest they’re getting, according to a quarterly Paths to Prosperity study by Santander US, part of the global bank Santander. Of those who do know their interest rate, most are earning less than 3%.

“There’s real opportunity for people here to better their financial health by being aware, and by being willing to take some action,” said Tim Wennes, CEO of Santander US.

A simple internet search turns up multiple banks offering high-yield savings accounts with 4% or even 5% interest. Banks are raising those rates in response to a dramatic increase in the prime lending rate, the rate banks charge their most creditworthy customers.

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Yet, customers have been slow to claim the higher rates. Another recent analysis, from Bankrate, found that one in five savers is earning 3% or more in annual interest on a savings account.

Why do savings accounts matter? Because they offer bank customers a way to stockpile funds to cover unexpected expenses, vacations and large one-time purchases. Financial experts say American households should aim to amass savings to cover at least three months of income.

“You want to have a certain amount of money in an emergency fund or a rainy-day fund,” Wennes said.

Many Americans aren't getting high-interest rates on their savings accounts

The new survey, released Monday by Santander, found a notable lack of financial literacy among consumers. Only one in 10 could provide correct answers to four questions about savings accounts:

Fewer than half of consumers could identify the definition of a high-yield savings account: generally, an account with a variable rate that pays a relatively high yield in interest.

Fewer than half could tell the difference between interest rate and annual percentage yield, the rate of return after compounding interest over a year.

Only one-third could identify the correct definition of a money market account, an alternative to the traditional savings account that often pays higher interest and typically includes some features of a checking account.

And only half could identify the definition of a certificate of deposit, a savings instrument in which the customer agrees to keep funds in the account for a set time.

The quarterly survey, conducted in September by Morning Consult for Santander US, reached a representative group of 2,201 banking and financial services customers in the middle-income range, with annual household incomes ranging from about $47,000 to $142,000.