How many times have you walked into a store — particularly a mom and pop shop — and saw some note taped in front of the cash register that says you can’t pay with a credit card unless you spend at least (fill in the blank) dollars?

Maybe you paid it no mind. But it was wrong. Merchants violated their agreements with credit card processing companies by placing limits.

Well, that’s not the case anymore.

Federal consumer protection laws affecting the use of credit cards, debit cards, and banking have changed or are about to. So, despite what you might have heard here a few times before — stop scolding the merchant with the sign. They can now set a $10 minimum limit to use a card as long as they don’t discriminate against one card or another.

Another big change you might have noticed, particularly if you access your bank account online, is the request to “opt in’’ to overdraft protection. Banks push pretty hard to get customers to say yes. And participation has been estimated at 70 percent or more.

But at a recent meeting on consumer issues at the Federal Reserve Bank of Boston, some involved in banking regulation questioned whether people know what they are opting in to. Opting in means you get overdraft protection. It also means you pay a hefty fee for spending more than you have in your account.

What happens if you don’t have that protection? Your payment would be denied at the register. So, would you rather have your debit go through when you don’t have the money to cover what you are buying — and pay $30 or so for the privilege — or get told that you need to pay a different way?

Some consumers said when they raised the question with their banks they were told that choosing overdraft protection would help them avoid the embarrassment of having their payment denied. I’d rather keep my money and pay a different way than make a donation to my bank.

On the bright side, anyone who opted in can later opt out (and vice versa). Remember, it’s not up to banks or other businesses to tell you the right thing to do. Their job is to make money. Your job is to protect yourself.

Mitch Lipka is a nationally known consumer columnist and runs TheConsumerChronicle.com. He lives in Worcester. You can find him on Facebook at http://on.fb.me/MitchLipka. He can be reached at ConsumerNews@Aol.com.

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