Measure M Sales Tax Bite Comes Monday : Revenue: Consumers will pay another one-half cent on the dollar, raising the total levy to 6 1/2%, for transportation.

It’s no joke: April Fools’ Day will be an especially taxing day for Orange County shoppers who suddenly find that just about everything costs a little more at the checkout counter.

That’s because at 12:01 a.m. Monday, the Measure M sales tax increase approved by voters last November will take effect, pushing the rate from 6 cents on the dollar to 6 1/2 cents.

To herald the hike, which is expected to raise more than $3 billion for transportation projects over a 20-year period, state officials on Thursday convened a news conference in El Toro to warn retailers that they are responsible for implementing the change and advise consumers to get their shopping done early.

“Make sure you check out by 11:58 p.m.” Sunday, quipped State Board of Equalization member Ernest J. Dronenburg Jr.

But many shopkeepers and shoppers on Thursday seemed unaware of the coming increase, despite notices recently mailed to all of Orange County’s 87,600 businesses advising them of the new rate and supplying them with a revised sales tax schedule.

Some of them said they were still adjusting to the drop in the tax rate at the beginning of the year, when a quarter-cent tax imposed to help finance reconstruction in the wake of the 1989 San Francisco earthquake expired.

“It’s changing again?” asked Yong Cha, 52, her eyes widening in disbelief as she leaned over the counter in the liquor store she operates with her son.

“I didn’t know anything” about the tax hike, Cha said, furrowing her brows and suddenly looking askance at her cash register. “Maybe my son knew.”

Cha’s confusion was shared by Valerie Larson, 34, of Anaheim as she sat outside a nearby bakery awaiting a ride.

“Wasn’t it 6 1/2% already because of the earthquake?” asked Larson, a single mother who works as a waitress. She shrugged upon being told that the earthquake rate was only 6 1/4%.

“Everything else is going up, so why not sales tax?” she said, her arms flung wide. “Now I’ll have to buy less.”

Others questioned whether the 20-year transportation plan funded by the tax hike would actually ease the traffic congestion plaguing Orange County.

“We pay enough in taxes already,” said Helen Owens, 34, of El Toro. “We definitely need something (for our transportation system), and yet I’m wondering if this will make a difference.”

The tax affects all “tangible personal property,” which excludes food and labor, but includes meals at restaurants and certain services, according to Dronenburg of the Board of Equalization. With Monday’s planned hike, Orange County joins 11 other counties--including Riverside and San Bernardino--that charge 6 1/2 cents for each dollar spent. Los Angeles County is scheduled to raise its sales tax on Monday to 7%.

Retailers will be required to collect the additional tax, risking penalties if they delay or forget. For most of them, though, implementing the hike merely entails a quick reprogramming of computerized cash registers. Few worry that the higher rate will mean loss of business.

“I’d be willing to bet that 60 to 70% of the people won’t even know” the difference, said Dave Delgiacco, manager of Peppino’s Italian Family Restaurant in El Toro. “Last time when it went back down to 6%, only one customer mentioned it to me. Only one.”

But in case customers do notice the bigger tax bite, Jesse Tsou, manager of a Chinese restaurant close to Peppino’s, has a response prepared. “Everybody knows it’s by the law. What can we do?”

Researched by: DALLAS M. JACKSON / Los Angeles Times

HOW NEW TAX WILL RAISE PRICES

The new half-cent sales tax will push up the cost of many items. Below is a sampling of products and their cost at the current 6% sales tax and the new 6.5% tax.

Advertised Has Will Item Price Cost Cost 1991 Cadillac El Dorado $32,440 $34,386 $34,548 Mcintosh IIsi computer 2,367 2,509 2,521 Leather sofa 1,500 1,590 1,598 RCA Camcorder 1,100 1,166 1,172 Toshiba 27-inch color TV 588 623 626 GE frost-free refrigerator 400 424 426 Man’s wool suit 330 350 351 Woman’s spring dress 150 159 160

All figures are rounded off to the nearest whole dollar.

Source: Various published advertisements County Tax Rates

County Amount Orange County 6.5% Los Angeles County 7.0% San Bernardino County 6.5% Riverside County 6.5% San Diego County 7.0% San Francisco County 7.0% Sacramento County 6.5%

Source: State Board of Equalization

Where Does Tax Money Go? The basic 6% sales tax is divided as follows:

What percentage of taxes does Orange County pay in comparison to other counties?

State: 73% Measure M: 8% County Transportation Fund: 4% City or County: 15%