Credit-card fraud, according to issuers, can be curtailed by a combination of customer precaution and computer-age technology.

One major proposal to tighten surveillance of credit-card transactions involves greater use of computer terminals to authorize credit sales.

Currently, only 10 or 12 percent of all credit transactions are authorized. This figure varies according to the floor limit (the price level at which authorization is required) of each merchant, according to Glenn Larson, vice president with sales and marketing for VISA U.S.A. in McLean.

One credit-card customer, for example, was surprised to find a $632 airline charge on his bill. The charge had not been checked because someone had used his charge account number for two separate ticket orders--both under the airline's floor limit.

However, by 1985, 85 percent of all VISA transactions may be authorized by computers, predicts Larson, who is involved in a pilot project to begin widespread distribution of computer dial terminals to merchants and member banks in November.

Another area of credit risk involves mail and phone order sales. A stolen credit account number can be used to order catalog merchandise, make hotel reservations or reserve airline seats.

Fraud in credit orders can be curbed if merchants who make their own deliveries require drivers to take an imprint of the orderer's credit card, claims Evelyn Hite, vice president of the consumer loan division of First American Bank of Virginia.

"The driver can say 'I need your card,' " says Hite, "before he takes the $700 stereo off the truck."

The biggest problem cited by several bank and credit-card company executives is the failure of credit-card holders to report a false charge until weeks later.

"Our system is very effective in stopping credit-card fraud, but it is a matter of not knowing it has occurred," says Larson. "In a survey taken two years ago of VISA issuers around the country, customers did not report lost or stolen cards until they received their statements in over 50 percent of the cases."

Customers who fail to report a lost or stolen card in a reasonable period of time (usually four days for mail delivery) are sometimes required to pay the first $50 of substantiated fraudulent charges. The credit-card issuer assumes the remainder of the loss.

Customers who discover a false charge on their statements and who still have their credit cards are also urged to set security investigations into motion immediately by contacting their issuers. These cases are termed merchant fraud; the merchant assumes all of the loss.

Credit account numbers are stolen by people who find the number on a discarded charge slip, or who deal directly with billing, or who riffle through a mail box to pick up a number and credit standing.

"Many people give out their account numbers over the phone, because they assume they are dealing with an honest person at the other end," says Edward Koster, security manager of Virginia National Bank.

"Callers may say they represent a bank and want to verify a charge account number, or they announce the person has won an all-expense-paid vacation if they will just verify their identity with their account number."

A dishonest sales person, says Larson, may use extra carbon tissues while imprinting a credit card, return the card and then fill out the slips for other purchases.

Fraudulent use of lost or stolen cards, which totaled $50 million in 1980 for VISA alone, is the result often of owners' carelessness.

Advises Koster: "Customers should think of credit cards as cash, because this is the way thieves look at it."

One third of the credit-card losses reported to Virginia National Bank, he says, resulted from people leaving their cards in their cars, usually in the glove compartment. Another 20 percent were stolen at a place of employment and 10 percent in motel and hotel rooms. Women, because of accessibility of their purses, accounted for more than 70 percent of the card thefts.

Larson says theft using only stolen account numbers is "minute"; Koster estimates it totals under 1 percent of total credit-card fraud.

Credit-card issuers list these rules of precaution for credit-card holders:

Report stolen and lost cards and false charges to your credit-card company immediately.

Keep credit cards on your person or locked up while in public places.

Inventory credit cards between financial statements.

Consolidate credit cards to three or less.

Destroy charge slips before discarding.

Keep a list of all credit accounts and numbers to speed reporting of theft.

Keep a record of all charges in order to verify debits on statements.

Do not give out charge account numbers over the phone unless placing an order. --