STARTING THIS week, credit-card companies that had been free to commit grand larceny will be forced to get by on the proceeds of petty theft.

Phase one of the Credit Cardholders' Bill of Rights became law yesterday, depriving the card-issuers of the right to pillage and plunder as they pleased.

The law - passed by the House by a 357-70 margin in April, with 90 ayes by the Senate in May - will ultimately deprive the card-issuers of the right to raise rates on a whim, even on accounts that were always paid on time.

Provisions like "universal default" allowed them to raise your rate if you or your spouse were late paying an unrelated bill with another company. Some used "double-cycle" billing, which allowed them to charge additional interest on previously paid balances.

We have all reached into our pockets at one time or another and found our credit-card company's hand already in there. But your personal horror story offers only a glimpse of the magnitude of the theft.

The Pew Charitable Trusts' "Safe Credit Card" project's report is a detailed look at one of the sweetest scams ever perpetrated on a trusting public.

The report found that issuers were allowed to "earn" an additional $10 billion by raising interest rates on 25 percent of accounts issued in the U.S.

About 93 percent of the cards allowed issuers to raise any rate at any time. The Pew report found that 87 percent of the issuers allowed automatic-penalty interest-rate hikes on accounts less than 30 days past due.

Pew found that all 400 of the cards that they examined included at least one practice that the Federal Reserve said was "likely to cause substantial monetary injury to consumers."

And here's the best part: Many of the banks issuing these cards were being kept afloat with bailouts financed with our tax dollars.

But, starting this week, issuers have to provide a 45-day notice before raising rates. Before that, they could raise your rate on two weeks' notice.

If that was all the law addressed, it would be like giving a bank robber the OK to rob the vault as long as he kept his hands out of the cash drawers.

But by February, when the bill is fully enacted, the restrictions will start to cut deeply into their reserves. Issuers are starting to get creative.

"These are for-profit companies," said Bill Hardekopf, of LowCards.com, a free, independent Web site that offers rate comparisons for prospective consumers. "When revenues are negatively affected, they always come up with ways to offset the impact."

JPMorgan Chase has increased its minimum payment rate from 2 percent to 5 percent for many cardholders. On an $8,000 balance, the payment would jump from $160 to $400 a month.

Balance-transfer fees are being raised from 3 percent to 4 percent at Bank of America. Chase hiked its balance-transfer and cash-advance fees to 5 percent.

Many card issuers are moving from fixed to variable rates because the law does not limit the amount variable rates can go up in the same way it does fixed rates.

New cardholders will find it harder to find cards that don't have an annual fee.

In February, we may see even more add-ons and higher fees. At that point, issuers will be limited in how far they can raise interest rates. They will be prohibited from applying new rates to old balances.

Double-cycle billing and universal defaults will be prohibited. Issuers will not be able to market to students under 21.

They will be required to offer current customers whose rates go up an "opt-out" that gives them five years to pay off the balance at the old rate.

"The stuff that went into effect this week is mostly about notification," Hardekopf said. It's good for consumers.

"But you've got to learn to notice the notices. Even 45 days is not enough if you are a procrastinator."

The Credit Cardholders' Bill of Rights won't protect you from yourself.

Send e-mail to smithel@phillynews.com or call 215-854-2512. For recent columns: http://go.philly.com/smith