Washington — No matter how many holiday bills you've paid this month, Carole Jones Dineen still will send out more checks. As fiscal assistant Treasury secretary, Mrs. Dineen is the nation's top bill payer. Her office issues approximately 54 million checks a month.
Since coming to Washington less than a year ago, Mrs. Dineen has been trying to bring the government's bill-paying and debt-collection operations into the 1980s.
''I would say the government is eight to 10 years behind the private sector, '' in using the most modern financial techniques, she says.
But the former Bankers Trust Company vice-president is quick to add that initial work modernizing selected government financial operations began before she joined the Reagan administration.
Big dollars ride on the matter of how efficiently the government collects its debts and pays its bills.
In the current budget year, for instance, Mrs. Dineen's initial efforts will trim the government's interest payments by about $700 million. That has been done by speeding funds into the government's pocket and holding them as long as possible, thus cutting the amount the Treasury has to borrow.
''What we have done is skim stuff off the top,'' she notes. At the moment some 314 projects to improve the way the government handles its cash are underway in conjunction with 20 departments and agencies.
And an in-depth study of cash management practices at the Treasury, Agriculture, Defense, and Health and Human Services Departments will highlight even larger potential savings when it is completed later this year, she contends.
Outside observers agree that the government's financial management practices were outmoded.
''There is just unbelievable room for improvement,'' says Wilson Johnson, chairman of the National Federation of Independent Businesses and co-chairman of the Grace Commission's task force on government financial asset management.
He notes that Uncle Sam still has some distance to go in getting his financial operations in order.
''I think candidly they have made a start and I am extremely pleased with that. At this point they are only half way to first base,'' he says.
While the specific techniques Mrs. Dineen uses are complex, the underlying concept is simple: She tries to speed up collection of money owed the government while delaying bill paying until the last possible legal moment.
To get faster collections, the Treasury hired a group of five banks, led by Citizens & Southern National Bank of Atlanta, to speed the flow of funds to the government from the 450 general accounts it holds in local banks.
''This allows us to assure the money moves on time,'' Mrs. Dineen says.
By making sure the money is sent to Washington within 24 hours, the Treasury will cut its interest bill this year by $19 million.
In a further bid to speed the flow of funds to Washing ton, she has spearheaded a nationwide system of lock boxes. Government agencies now hire post office boxes in several centrally located cities and pay a bank to remove checks from each box several times a day and deposit the money into the government's account. By putting lock boxes in cities where a heavy volume of payments are made, funds move to the Treasury faster than if the payments were all sent to a less precisely selected location.
Mrs. Dineen also is trying to hold onto government funds as long as possible without violating a federal law that requires the government to pay contractors promptly.
To avoid the late payment penalties the law imposes, some agencies were paying their bills early, thus prematurely depriving the government of the use its money and pushing up borrowing costs. Since late 1983, the Treasury has paid bills of $25,000 or more by sending the payment electronically to the creditor's bank at the last legal moment.
''We are not'' playing payment games, Mrs., Dineen insists. ''We will give you your money exactly the day it is due and we promise that. But not early.''
Although Mrs. Dineen keeps a tight watch over government funds, she does not fit the stereotype of an accountant, hunched over a ledger wearing a green eyeshade. She speaks in a quiet, friendly manner, smiles readily and dresses in well-tailored business suits.
Mrs. Dineen and her husband, a New York City-based corporate lawyer, live apart during the week.
On Fridays she flies to Connecticut to meet him at their home there. Sunday evening they drive to their New York City apartment and on Monday she takes the 7 a.m. shuttle back to Washington where she lilves in an apartment.
''I don't have a lot of spare time,'' she says.