An anti-trust settlement between merchants, credit card companies, and banks has cleared the way for retailers in 40 US states to add surcharges to credit card payments, Reuters reports. It's up to individual retailers to decide whether to apply the fee — which can be equal to the cost of accepting cards — and as Reuters notes, the fees will still be illegal in California, New York, Texas, and seven other states, and won't apply to debit card purchases. The suit dates back to 2005, when merchants accused Mastercard, Visa, and other companies of conspiring to fix credit card fees. Historically, merchants have paid the fees for credit card transactions, but some have argued that cash users also end up footing the bill; merchants are said to raise prices to cover the cost of card use, forcing cash users to pay more than they theoretically should. Reuters says the new fees went into effect January 27th, so credit card users could see higher bills at stores in the near future.