You all know a credit card when you see one; now there's a debit card

Some people would be lost without their credit cards. These individuals use their cards for everything -- from clothes shopping and the most extravagant dinner to running down to the corner store for a bottle of shampoo or a spool of thread.

Other people shudder visibly when a store clerk asks whether they will pay by cash or charge. "Cash, of course," they say, appalled to think they look like the type of person who would carry "plastic money."

The Interbank Card Association has come up with a compromise for these opposing spenders: MasterCard II.

According to Interbank, MasterCard II, was introduced as an effort to "let consumers use their own money without carrying cash or checks." It looks like a credit card, but it's more like a check. MasterCard II, similar "debit cards" put out by some local banks, and Visa USA dip straight into the holders' account at his local bank, savings and loan association, or credit union.

Credit cards establish a line of credit for each customer. All purchases made on the cards are considered a cash advance -- a sort of mini-loan -- which is then subtracted from the credit line. Customers are then responsible for repaying this "loan."

Debit cards do not allow customers to spend money they do not have. Instead, the amount of the purchase is subtracted directly from the holder's bank account. If a purchase is made with insufficient funds, the store will not be paid, much as if it had received a bad check. Some banks allow a debit card holder, when his checking account is exhausted, to go into the red through a credit facility.

Sheldon Gollub, a spokesman for the American Bankers Association, says the debit card concept is not new. "What is new is that international organizations are putting them out." Interbank's card will be accepted in 140 countries.

Visa USA also issues debit cards and, according to spokeswoman Cynthia Chadwick, the cards are becoming more and more popular.

Visa introduced the debit card in 1975. It is more popular abroad, but here in the United States there are 1.2 million debit card holders (as of June 1979). "But we expect dramatic growth in this particular method of payment," Miss Chadwick says.

Interbank attempted to market a similar card, called the Signet, in 1975. Apparently it was not received well, because Signet was dropped from the MasterCard line. An Interbank official would not offer an explanation for its failure.

Interbank is a nonprofit trade association. It is responsible for setting standards and authorizing and licensing banks for membership in its association. After admission to Interbank, member banks may issue MasterCards to customers according to their own standards of credit.

Financial institutions licensed to distribute the new MasterCard II will also be free to set their own customer limit. According to an Interbank information sheet, "Participating institutions can tailor MasterCard II programs to meet specific competitive needs."

Visa's cards are distributed to banks in a similar manner. Many banks attach their own name to the Visa logo, but retain the blue band insignia so the card will be internationally recognized.

Timothy Lynch, a spokesman for Interbank, says he believes the MasterCard II will be "quite successful. There are some good indications that banks will sign on." He explains that many people don't like to use credit cards "for one reason or another."

One nonuser says she doesn't trust herself. "I know I will abuse the cards once I get my hands on them, so I don't let myself near them." Other nunsuers reason that their lack of credit cards is a form of discipline -- they buy only what they can pay for. If they can't afford it, they don't buy it. Also, some just don't like the bills coming in every month.

Mr. Lynch adds that a lot of spenders like to vary their transactions. "They like to pay for some things by card, some by check, and some with cash." In this way, no one account gets overdrawn, they maintain a reasonable balance in their bank account, and they don't have to carry around large rolls of cash.

But those who refuse to carry credit cards may be in for some trouble. It is not always safe to carry large sums of cash. Checks aren't accepted everywhere. Very often, when the buyer leaves the state where he has an account, his checks become useless. Traveler's checks may be inconvenient and are not always accepted.

As a result, the nonuser may find it difficult to shop out of town. Renting a car or reserving a hotel room could well be difficult, since most rental agencies and hotels require a major credit card. John Britton, manager of news and information for the Hertz Corporation, explains that customers may rent cars for only if the person can first be "checked out -- in other words, we'd check to see that the person has a phone in his name, that he is employed, and that he maintains some credit line at a bank."

However, the major credit card holder is assumed by Hertz to be somewhat reliable, having been checked out already by the financial institution. "In a sense, the credit card is vouching for the person. He can be trusted with a $7, 000 piece of machinery."

Mr. Britton said that yes, Hertz would accept the new debit cards -- but only the major ones. "Many local banks issue cards," he explains, "but we require that it be a major debit card for our purposes, just the same as we require a major credit card."