WASHINGTON (AP) _ Taxpayers seeking assistance at Internal Revenue Service offices are running into more locked doors this year.

Service hours at many offices around the country have been trimmed and some temporary satellite offices have been closed, IRS spokesman Frank Keith said Tuesday.

An example: Eight small offices in northern and central Florida have restricted customer service hours to three days a week. Keith said the cutback is part of an IRS strategy to handle more assistance, more efficiently, by telephone.

He acknowledged that the number of taxpayers helped at IRS offices had dropped to 2.4 million through early March, compared with 2.8 million during the same period of fiscal year 1995.

But the number of people helped by telephone has increased to 16.3 million, up from 15 million. So, overall, more people are being helped, he said.

Also, this year, tax information is available over the Internet. Through March 10, 26.5 million computer users have visited the IRS' homepage.

However, Rep. Charles Canady, R-Fla., who fielded complaints about the office-hour cutbacks in Lakeland, Fla., said the IRS' telephone performance offers a poor alternative.

``Some constituents were faced with the experience of going and finding the door locked and then going home and getting nothing but a busy signal,'' he said.

Studies by Congress' General Accounting Office show it's become increasingly difficult to reach the IRS by telephone. In 1995, only 8 percent of calls to IRS toll-free lines were answered, down from 21 percent in 1994 and 58 percent as recently as 1989.

IRS officials believe access has improved over last year, when delayed refunds as part of an anti-fraud crackdown generated many calls. But telephone access statistics for this year aren't available yet.

Canady and Rep. Jim Lightfoot, R-Iowa, are pressing the agency to restore last year's level of walk-in service. Lightfoot plans to question IRS Commissioner Margaret Milner Richardson about the cutback at a hearing of his House Appropriations treasury subcommittee on Thursday.

``I will not tolerate the IRS inconveniencing taxpayers,'' he said.

The House-passed version of a spending bill keeping the government operating through the end of the 1996 fiscal year would require the IRS to restore walk-in service to last year's levels.

However, even if the IRS walk-in office provision is enacted into law, it probably would come too late to make a difference this year. The April 15 filing deadline is little more than a month away.

In a letter to Canady, Henry O. Lamar Jr., director of the IRS' Jacksonville, Fla., district, blamed the office-hour cutback on ``recent budgetary constraints.''

The IRS budget for 1996 has been trimmed to $7.4 billion from $7.5 billion the previous year. But GOP lawmakers point out that the agency's budget for taxpayer services has risen by $33 million to $329 million. That's enough to hire 237 additional employees.

``It's pretty clear'' the IRS was trying ``to create a little bit of a flap over their budget'' by cutting one of its most visible services, Canady said.