The banking industry will take the first step toward paying interest on checking accounts this Wednesday and bankers are not exactly sprinting to the starting gate.

Effective Nov. 1, banks will be able to offer their personal customers - but not business - a service providing automatic transfer of funds from savings to checking accounts.

Customers will be able to keep their money in a savings account, earning 4.5 or 5 percent interest, until they need it to cover a check. When a customer who signs up for the service writes a check and there is not enough money in the checking account to pay it, the bank will automatically tap the customer's savings account.

The procedure sounds simple enough, but the ways of doing it and paying for it are not. A Washington Post survey of a dozen banks in the District of Columbia, Maryland and Virginia found almost that many variations in the rules and pricing of automatic transfer plans.

"This is a totally new product for banks. It represents such tremendous complexity as far as systems and pricing are concerned I'm not surprized that none of them are alike," said Tim Holland, vice president of American Security Bank of Washington.

Some banks are requiring minimum balances - $200 to $2,000 - in savings or checking accounts or a combination of the two but others have no minimums. Some charge a flat monthly fee - $2 to $6 - for an automatic transfer account, while others are collecting a small fee - 25 cents, 50 cents or $1 - for every transfer or for every day a transfer is made, regardless of the number.

And some banks won't offer the service at all, or won't offer it for another month, or are waiting until the last minute to announce their plans so they can size up the competition.

The marketing manager of one big Virginia bank described the situation as "positive uncertainty" meaning, apparently, that he isn't sure what will happen but he thinks it will be good.

The uncertainties include how many customers will want the service, what they will be willing to pay for it and, most important, how it will effect banks' deposits and profits.

Though not participating in the system, the savings and loan industry could be effected by it if, as many in the financial community believe, it leads customers to shift funds from S&Ls to bank savings accounts, where it is only a check away. The threat of disintermediation - transfering money from S&Ls to banks - is so great that the savings institutions have filed federal lawsuits to try to prevent the automatic transfer plan from going into effect Wednesday and still could succeed in getting a temporary injunction.

Even customers who don't want or need automatic transfers are likely to fee their impact, because the new service is expected to increase competition between banks and to lead to changes in the way banks charge for their services.

Estimates of how popular automatic transfers will be range from that of John Nickles, vice president for marketing of Maryland National Bank, which does not plan to offer the service, that "our research indicates there will not be very wide acceptance" to projections by United Virginia Bank Vice President O. B. James that 30 to 40 percent of that bank's checking accounts will be in automatic transfer accounts by early next year.

Even the American Bankers Association stresses that automatic transfers are not for everyone; some customers will pay more for the service than they will gain in interest by shifting money from their checking to savings accounts.

Local bankers estimate that customers will have to keep $700 to $800 in the savings side of their automatic transfer accounts to earn enough interest to cover the service charges. They add that the balances will have to be larger than that if the customer writes a lot of checks. The bigger the balance the customer now keeps in a checking account, the more attractive and profitable the automatic transfer account will be, bankers agree.

Besides Maryland National, the Dominion Bankshares group in Virginia is not offering automatic transfer service. Another major Virginia bank holding company, First and Merchants Corp, is aiming for a Dec. 1 start-up.

The Federal Reserve Board, the Federal Home Loan Bank Board and the Federal Deposit Insurance Corp. are closely monitoring the plans and requiring banks to have special paired savings and checking accounts for automatic transfer customers. Bank regulators rejected the name one local bank planned to use for its service because the name implied the bank was paying interest on checking, which still is prohibited.

One of the smallest banks in the Metropolitan Washington area, Central National Bank of Maryland, was the first to announce its terms, and the plan it launched on Sept. 15 is still among the cheapest and simplest. Called "Zero Balance Checking," the plan requires a $1,000 savings account balance and has no monthly service charge or fee per check.

Central National of Maryland President Tom Moore said the service was deliberately priced low to attract business to the Montgomery County bank, but still projected only 5 percent of its total deposits will go into the plan. He figures the bank can make money by investing the $1,000 balances in consumer loans that will provide a 10 percent return, more than enough to pay 5 percent interest on the savings account and cover the cost of the system.

First Virginia Bank's Saving-Checking Automatic Transfer (SCAT) account is similar, providing free transfers with a $1,000 average - rather than minimum balance. If the average balance falls below that, the customer pays $3 a month, but still can profit from the system if the savings balance remains above $720, said John Baker, executive vice president of First Virginia.

Instead of sugar-coating the cost of the system in minimum balances, many Washington area banks are using what bankers call explicit pricing - charging the customer for the services rendered. That concept already has largely eliminated free checking from major banks here and as it spreads could mean more direct charges for other bank services.

Suburban Trust of Maryland requires no minimum balance for its Bankamatic Transfer accounts and imposes no other charges unles the transfer provision is used. Then there is a $3 monthly charge plus 25 cents for every day that a transfer is made.

Many banks are charging by the transfer day because it costs just as much to turn on the computer to do one transfer a day as to do half a dozen. Customers who hope to minmize their transfer charges by writing all the checks the same day probably will fail because of the varying lengths of time required for checks to clear.

Banks are counting on customers to keep more than the minimum balances in their accounts, based on the experience of New England banks which were allowed to experiment with a similar plan and found that $1,000 minimum balance requirements produced actual balances in the $2,000 to $3,000 range.

Riggs National Bank in Washington has two different plans, both requiring a $1,000 minimum balance in a savings account. If the customers keeps a $500 minimum in checking, there is no monthly charge; without that minimum, there is a $3 monthly charge.

"If the balances are just $500 and $1,000, the account will not be profitable," said Riggs Senior Vice President Melvin Chrisman. "But we know the averages run over that." Added Chrisman, "We know we are on the low side of the charges, but we think we know what it costs to do business and we think it will be profitable."

Chrisman noted that a Riggs customer will earn $50 a year interest at 5 percent on the $1,000 minimum savings balance. Opting for a zero-balance checking account will cost $36 a year in service charges, producing a $14 savings. But he pointed out that interest earned on savings accounts is taxable.

The Riggs plan also has a complication that makes price comparisons trickier: The bank transfers funds from savings to checking accounts only in $100 increments to simplify the bookkeeping for the bank. Most other banks transfer funds in the exact amount needed to cover checks.

Riggs' biggest D.C. rival, American Security Bank, plans to offer its customers three options on its Money Maker accounts, all tied closely to its reegular checking account plans. One uses a zero-balance checking account with all the money in savings, another keeps some funds in each account and the third utilizes the automatic transfer service as an alternative form of overdraft protection for persons who don't want the usual overdraft credit or don't qualify for it.

"Probably any one of our plans would be okay for anybody who walks in the door," said American Security Vice President Holland, "but each situation is so complex" that the bank of first will not advertise the plans, instead training it employes to cousel customers on the best choice based on their balances, checking activity and needs.

American Security requires only a $200 minimum savings balance and charges: a $1-a-month maintenance fee plus 10 cents a check. American Security's plan has a complication as wwell: The bank credits its customers 21 cents per month against their checking charges for each $100 of average balance in the checking accounts.

Despite the apparent differences in the charges of the District's two biggest banks, officials of American Security and Riggs agree that the breakeven point for customers using their plans is a $750 to $800 savings account balance.

Union First National Bank of Washington, the third largest bank in the District, charges 50 cents per transfer day, and imposes no other charges if the savings balance is more than $5,000. With a savings balance between $2,000 and $5,000, there is a $2 charge, which doubles if the balance is below $2,000.

Similar plans are offered by American Bank of Maryland and First American Bank of Virginia, which are also part of the Financial General Bankshares system.

National Bank of Washington requires a $1,500 deposit to open a Trans-Flow account and charges a $4 monthly maintenance fee whether or not the transfer privilege is used, but does not impose a transfer charge. NBW is paying 4.5 percent interest on savings but most other banks pay 5 percent.

Suburban Trust of Maryland's Bankamatic Transfer plan requires no minimum balance and charges $3 a month plus 25 cents per transfer day and requires no minimum balance. But a spokesman cautioned, "in order amount in savings to cover the monthly charges. For the average person, it probably will not work out well unless they are willing to pay for the convenience of it."

Unite Virginia Banks' United Accounts require no minimum balance and have no item charge, but base the service fee on the combined balance of checking and savings accounts. Above $1,500 there is no charge, from $500 to $1,500 there is a $3 monthly charge and below $500 there is a $6 charge.

Virginia National Bank calls its system Automated Transfer Service and has no minimum balance requirement, collecting a $4 monthly charge and 20 cents per transfer day.

Some bankers acknowledge privately that charges are meant to discourage small accounts. It's impossible for the banks to make money on the consumers are insignificant, they contend.

Bankers suggest the greatest uncertainty about automatic transfer is their effect on the traditional distinction between savings and checking accounts.

"Some people don't want to be able to dip into their rainy-day savings," explained Margie Hurley, marketing director of Union First.

A widely quoted study made for the Iowa Bankers Association found a majority of bank customers in that state said they would not use the system because it "directly threatens their conception of how savings and checking accounts should be used."

"For the majority of consumers, savings accounts are secure nest eggs for future planned expenditures while checking accounts are convenient means for paying bills and keeping financial records," the Iowa study concluded.