Washington ? As if tax forms weren’t complicated enough already, the sweeping tax law enacted last year is forcing taxpayers to grapple with dozens of changes. One new line alone has led to more than 1 million errors.

Even with the tax relief President Bush signed, the tax laws are “an abomination” and new government reports will illustrate the “absurdities,” Treasury Secretary Paul O’Neill said Thursday. He pledged anew to try to simplify tax laws, but the White House could make his job more difficult: Bush is proposing new tax credits that would add more complexity.

The 10-year, $1.35 trillion tax cut passed by Congress and signed by Bush in June made 441 tax law changes, according to Kansas City, Mo.-based H&R Block Inc. Most will be phased in gradually during the decade, but some important ones are in effect.

The Internal Revenue Service expects about 132 million individual returns this year, including a projected 45 million to be filed electronically.

The deadline is midnight April 15 in most of the country.

Through Feb. 15, average refunds were $2,210, almost 12 percent more compared with the same period last year, mainly because of the lower tax rates and a bigger child tax credit, according to statistics released Thursday. E-filing by people using home computers is running 38 percent ahead of last year.

Millions of taxpayers got some benefit of the big tax cut in the form of rebate checks of up to $300 for individuals and $600 for married couples that were mailed out during the summer and fall.

But Congress, seeking to spread the wealth, authorized a new line on this year’s tax forms for people to claim a credit if they got no check or received less than the full amount. This credit is sowing confusion; the IRS has received more than 1 million returns with errors related to it.

Other important changes affecting 2001 returns:

The child tax credit for eligible families rises from $500 to $600.

Alternative minimum tax exemptions rise by $4,000 for married couple filing jointly, $2,000 for individuals and heads of households.

Income tax rates, except the 15 percent rate, were reduced by 1 percentage point on July 1, 2001.