The new "rule" took effect yesterday, Sunday, that allows merchants to add a surcharge to your purchase. What's the rule exactly? Who's taking part? Why is this happening? Read on for details:

Visa and Mastercard have agreed to let merchants add a service charge that equals the cost that the credit card companies charge the merchant for swiping a card. This can be anywhere up to 3.5% of the purchase. However, stores can charge up to 4% if they feel the need to.

So why the change? It was all brought about as part of a settlement from an anti-trust suit brought upon from the merchants to the credit card companies.

What is effected? Just credit card transactions. Debit card transactions are not effected  by the new rules.

Who's taking part and adding the surcharge? Wal-Mart, Target, Sears, and Home Depot have gone on record with NBC News saying they aren't interested in raising your cost at the register. Good news for us though. Even if any store wants to take part in the new rule - New York state has rules against credit card surcharges.

There are some more confusing parts to the new rules that really aren't worth getting in to as they just mud down the basic info.

But think about this before swiping your card as credit again. Though the above stores mentioned they wouldn't add the surcharge, they can if they want. But! They already factor in the cost of the credit transaction into their prices so it would just be another way for them to essentially make money if they choose.

In the end, all stores that add the surcharge must display a sign at their entrance explaining such. Online retailers won't have to explain any surcharge until the customer reaches the payment page for their transaction - which is mostly the last step and kind of sucks if you really don't want to pay that charge and will have wasted your time.