After a bumbling start late last year, President Carter's new wage-price guidelines program is coming along somewhat better than expected.

Recent indications show the program is gaining such wide acceptance among businessmen and workers that even its advocates are a bit startled.

Alfred E. Kahn, President Carter's anti-inflation adviser, told Congress last week the administration is "simply amazed at how seriously people are taking this program." Kahn said he now expects "90 percent compliance by business."

And officials at the Council on Wage and Price Stability say businessmen are so scrupulous about checking pricing policies with the agency that "it's almost as though they regard these as mandatory controls."

The better-than-expected reception has brought mixed blessings for the administration. The council, for example, has had to seek 90 new staffers just to handle the volume of inquiries. And more regulations are on the way.

At the same time, however, the program's apparent success is making it more difficult for the administration to persuade Congress to pass Carter's new "real wage insurance" tax-credit proposal designed as a sweetener for labor.

After Kahn exulted last week on the success of the wageprice program, Rep. William R. Cotter (D-Conn.) asked: "Then why do you need real wage insurance?" Several other members of Congress have asked similar questions.

There are these developments:

Although some economists still maintain that the guidelines are unlikely to slow inflation much, the direct response -- particularly from business -- has been more favorable than expected.

The Council on Wage and Price Stability reports receiving an average 2,500 calls a week from business firms around the country, virtually all for information on how to comply with the price standards.

Council officials say they now expect widespread compliance from business, particularly the big Fortune 500 firms the administration had been trying to enlist first.

Although labor has responded less enthusiastically, Carter officials say that despite grumbling from the AFL-CIO, individual union leaders generally have been cooperative and are seeking to comply with the guidelines.

The administration's first brush on a relatively major collective bargaining contract -- the oil workers' negotiations last month -- led to a settlement all sides agree would have been higher without the program.

And last week, Douglas Fraser, president of the United Auto Workers union, endorsed not only the guidelines but Carter's real wage insurance plan as well -- a step that could make a crippling auto strike this fall less likely.

The guideposts have been accepted by the public as a national standard for pay and price increases. Every week, there are signs that both public and private wage-price decisions are made with the guidelines in mind.

Only recently, the nation's purchasing agents agreed to protest any price rise that do not appear to comply with the guidelines. And Washington's recent taxi-fare increase was compared to the price guideline. Other examples abound.

Even detractors such as Marvin H. Kosters, a former Nixon administration wage-price controller who vigorously opposes the guidelines program on principle, concede it's faring better than expected.

(Like many conservative economists, Kosters still believes the plan won't help in bringing prices down. But, he says, on reflection, "It could help hold down wages a notch.")

Most analysts still believe the guidelines will have relatively little impact, at least in economic terms. The White House estimates the program could shave half a percentage point from the inflation rate, but that's considered optimistc.

Despite last month's modest victory involving the oil workers' contract, the program still must undergo its first big test -- the Teamsters union contract negotiations next month.

And the administration still faces possible legal challenges over its plan to deny government contracts to firms that flout the guidelines. The first such actions, if any, won't come for another few months.

But the good beginning could work to the administration's advantage when officials go before a House Banking subcommittee next week to seek an extension of the wage-price agency's basic authority.

Unless there are some suprises, congressional insiders see relatively smooth sailing for the renewal legislation -- with no major attempts by opponents either to use the measure to revamp the guidelines or riddle them with exceptions.

No really serious assessment can be made until the program passes its first watershed in the Teamsters negotiations next month. Analysts still say if the Teamsters flout the pay standards entirely, the wageprice plan is doomed.

Moreover, despite the heavier-than-expected corporate interest in the price guidelines, actual compliance could fall short of proponents' hopes.

White House officials concede a significant number of firms may balk at signing certificates of compliance when the enforcement program gets underway next month.

If so, the administration could be pushed to some early tests.

Economists warn that despite the initial interest in the program, inflation is likely to be severe in the next few months, with both the producer and consumer price indexes showing sharp increases from previous food and fuel price rises. If the guidelines have any impact, it won't be felt until later.

Nevertheless, compared to its wobbly start late last fall, the plan seems in decidedly better shape than anyone predicted. There may even be some chance the administration will pull it off -- perhaps to its own amazement.