Talk about taxing:

Only one of three elevators at the Internal Revenue Service's downtown taxpayer assistance office was in service yesterday morning, the last tax filing day.

Claritha Nichols, assistant division chairman of taxpayer services, said one elevator was broken and the other was being used by another tenant in the building to transport papers.

That left one elevator to serve the hundreds of taxpayers who crowded into the building to get to the seventh and eighth floors for forms and last-minute help in filling out tax returns.

Nichols said the morning bottleneck at the elevator didn't seem to slow down taxpayers, however. "They got here somehow," she said. Moreover, Nichols said she wasn't aware of any taxpayer complaints about the lack of elevator service.

By noon all three elevators were operating normally.

The eighth-floor office handed out forms to about 3,000 taxpayers yesterday, compared with about 500 to 1,000 a day last week, Nichols said.

IRS group manager Joan McClean said that the six-person staff in Room 703 worked with 1,020 taxpayers seeking personal taxpayer assistance. That compares with about 650 to 700 taxpayers a day last week and about 300 to 400 a day the previous week.

William Bryant, 40, a local parking lot manager, said he had come for help because the forms are difficult to decipher and because "each year they change them." He said that trying to keep up with the annual changes in tax forms is like trying to drive down a road that changes direction every year -- "You can end up in a creek either way."

While Bryant was waiting for a self-help taxpayer class to start, a stream of other taxpayers filed through the room, seeking answers to an assortment of questions. Most of the queries were related to 1984 federal taxes, but there were some exceptions:

* One woman arrived seeking a Maryland tax form.

* Another woman wanted to know how to fund an Individual Retirement Account.

* A college student sought tax tables for the past three years so that he could file his overdue tax forms.

Many of those waiting in line came to file applications for automatic extensions. "I haven't received my W-2 forms from Pennsylvania, and I can't file without them," one woman explained. "So I am here for an extension."

A young man in line ahead of her turned around and announced: "You and me both, baby."

Dom LaPonzina, an IRS representative, said that Form 4868 -- the application for automatic extension -- was by far the most popular form of the day. He described the business at Washington IRS offices as "a steady flow."

IRS workers got through the day, which ended at 6:30 p.m., by drinking chocolate malts. "I'd say we went through about seven," said Electra Geer, one of the six persons on duty in Room 703.

Among those who benefited from her assistance was Daniel F. Mulkey, 65, a retired government engineer who lives in Southeast Washington. After nearly three hours of waiting, listening and computing, Mulkey was done with his taxes. And, according to the figures, he has a refund of about $80 coming to him.

That might be cause for some taxpayers to celebrate. But Mulkey is taking a wait-and-see attitude. "I'll believe it when I see it," he said.