Mailing dates Taxpayers should generally expect to receive tax refund checks based on the last two digits of their Social Security numbers, according to the IRS. Married couples filing jointly, the first Social Security number on the return will be used. 00-09: Week of July 23. 10-19: Week of July 30. 20-29: Week of Aug. 6. 30-39: Week of Aug. 13. 40-49: Week of Aug. 20. 50-59: Week of Aug. 27. 60-69: Week of Sept. 3. 70-79: Week of Sept. 10. 80-89: Week of Sept. 17. 90-99: Week of Sept. 24.

He proclaimed the $1.35 trillion tax cut, most of which takes effect slowly over the next decade, the first achievement for a ``new tone in Washington.''

Such broad tax relief has happened just twice since World War II - President Kennedy's tax cuts in the 1960s and President Reagan's in the 1980s - Bush told a packed White House audience of near-giddy Republicans and some Democrats.

``And now it's happening for the third time,'' Bush said. ``And it's about time.''

Rebate checks, most between $300 and $600 will be mailed beginning July 20 to every American who paid taxes this year. Eventually, income tax rates will drop, the child credit will double and the estate tax, which Bush calls ``the death tax,'' will die.

``Most families can look forward to a $600 tax rebate before they have to pay the September back-to-school bills. And in the years ahead, taxpayers can look forward to steadily declining income tax rates,'' Bush said.

Democratic opponents complained that the wealthiest 1 percent of taxpayers will reap more than one-third of the new law's benefit. ``For tens of millions of Americans, the check is not in the mail,'' said Rep. Charles Rangel, D-N.Y.

Within an hour of the signing, House Minority Leader Dick Gephardt, D-Mo., opened up the possibility of rolling back some provisions in order to meet spending needs or accommodate any shortfall in the projected $5.6 trillion budget surplus that Bush is counting on to offset tax cuts.

There were no second thoughts in the East Room.

Republican leaders and the handful of Democratic lawmakers who helped push the bill through Congress - including Georgia's Zell Miller, New Jersey's Robert Torricelli, Louisiana's John Breaux, and Montana's Max Baucus - surrounded the president and grabbed for the 10 souvenir pens he had obligingly used to work through his signature letter by letter.

The package was $250 billion smaller than the version Bush had campaigned for and made a must-pass centerpiece of his first six months in office. Nonetheless, the president claimed vindication over political foes who had said his tax cut proposal was too big.

``Today it becomes reality,'' he said.

First lady Laura Bush, who is rarely seen when her husband conducts business, took a front-row seat, just one sign that this was a most special occasion for the young Bush White House. Three charter buses deposited members of Congress at the North Portico. Senior White House political strategist Karl Rove bounced through the East Room slapping backs and shaking hands two at a time. Vice President Dick Cheney, Bush's chief operative on Capitol Hill, slipped into the ceremony unannounced but for the clapping of the first lawmaker to spot him.

A grander ceremony planned for the South Lawn was chased inside by rain, so the dozens of guests who couldn't fit in the East Room were seated before TV monitors in the Grand Foyer. A grinning Rick Lazio, who lost last year's New York Senate race to Hillary Clinton, squeezed into the party that capped years of GOP frustration as former President Clinton blocked or vetoed several previous tax cuts.

Rep. J.C. Watts of Oklahoma, the fourth-ranking House Republican, told colleagues in a memo that as the refund checks go out to constituents, Republicans should ``take every opportunity to remind them who is working to give them more of their own money back to meet their own priorities, not Washington's.''

In addition to the refund checks and gradual income tax cuts - which include creation of a new 10 percent bottom rate - the measure eases the marriage penalty paid by millions of two-income couples, gradually doubles the $500 child credit and contains breaks for increased retirement savings and education.

House Republican leaders said they will attempt to pass legislation this year to eliminate the ``sunset'' expiration date and make the tax cuts permanent. But the Democratic majority in the Senate, installed after Vermont Sen. James Jeffords' switch from the GOP to independent, could make it difficult for that measure or any other House GOP tax cuts to pass this year.

Bush renewed his efforts Thursday to cultivate good relations with key lawmakers. He had what aides called a cordial meeting in the Oval Office with moderate Sen. Lincoln Chafee, R-R.I., and had Daschle to dinner at the White House.

The bill is H.R. 1836.