More than a dozen states are declaring sales-tax holidays this year, allowing consumers to shop tax-free-largely for back-to-school items including clothing, computers and supplies-for a limited period of time.

   At least 13 states and Washington, D.C., will waive sales and use taxes for several days in July or August, including four new states: Alabama, Maryland, Tennessee and Virginia. New York is currently running a year-round exemption on clothing and shoes (and items used to make or repair clothing) costing less than $110, while Massachusetts has proposed a tax break although it hasn't been enacted yet, according to CCH Inc., a tax-information provider based in Riverwoods, Ill.

   "There's not a lot of evidence that tax holidays increase sales, but they're popular with retail merchants and, needless to say, families with back-to-school expenses," says Dan Schibley, a CCH state-tax analyst.

   Here's a quick summary of the states' tax breaks:

Alabama: Includes clothing costing $100 or less per article; single purchase of computers, software and school computer supplies costing $750 or less; noncommercial purchases of school supplies and instructional materials up to a sales price of $50 per item; and noncommercial purchases of books up to $30 each, according to CCH. Runs Aug. 4-6.

Connecticut: Clothing and footwear costing less than $300 are exempt from sales and use tax from Aug. 20 to Aug. 26. This replaces the regular exemption on clothing and footwear - costing less than $50 - which remains in effect for all other periods; the latest tax holiday excludes athletic or protective clothing and footwear, jewelry, handbags, luggage, umbrellas, wallets and watches.

District of Columbia: School supplies, clothing, accessories and shoes costing $100 or less are exempt from August 5-13.

Florida: Books, clothing, footwear and certain accessories with a sales price of $50 or less per item, as well as school supplies with a sales price of $10 or less per item, are exempt from sales and use tax. But you can forget about the Mickey Mouse T-shirts: the break doesn't apply to sales within a theme park, entertainment complex, public-lodging establishments or airports. Runs July 22-30.

Georgia: Sales and use tax doesn't apply to certain school supplies, up to $20 per item; clothing and footwear, priced at $100 or less per article; computers, computer-related accessories and energy-efficient products for noncommercial use, for a single purchase of $1,500 or less. Runs from August 3-6.

Iowa: No sales tax, including school and local option sales taxes, will be charged on clothing or footwear that sell for less than $100 per item. Certain accessories won't qualify for the break, which runs August 4-5.

Maryland: Applies to clothing and footwear (excluding accessories) costing $100 or less. Runs August 23-27.

Massachusetts: Proposals for a 2006 tax break are still pending in the Massachusetts legislature, though it's unclear if they'll pass. For the past two years, the state declared a sales tax holiday for the second weekend in August, when retail sales of practically any item costing $2,500 or less were exempt, CCH says.

Missouri: Clothing and footwear (excluding certain accessories) costing $100 or less; school supplies costing $50 or less; computer software with a taxable value of $350 or less; and personal computers and computer peripheral devices sold for $3,500 or less. If less than 2% of a retailer's merchandise qualifies for the tax holiday, the retailer must offer a tax refund in lieu of the tax holiday. Runs August 4-6.

New Mexico: Clothing or shoes sold for less than $100 (excluding items primarily for athletic or protective use); computers (excluding handheld computers) priced at $1,000 or less, including monitors, speakers, printers, or related items sold for no more than $500; notebooks, paper, writing instruments, crayons, art supplies, paper clips, staples, staplers, scissors and rulers priced under $15; book bags, backpacks, handheld calculators, maps and globes priced under $100. Retailers are not required to participate. Runs August 4-6.

North Carolina: Clothing and school supplies priced at $100 or less; sports and recreation equipment priced $50 or less; computers priced $3,500 or less; and computer supplies costing $250 or less. (Clothing accessories, protective equipment, furniture and rentals are not exempt). Runs from August 4-6.

South Carolina: Clothing, clothing accessories, footwear, school supplies, computers, printers, printer supplies, computer software and linens for the bed and bath are exempt from state and local sales tax. Certain items, including, but not limited to, jewelry, cosmetics and furniture, are not exempt from tax. Runs August 4-6.

Tennessee: Clothing and school supplies costing $100 or less; computers costing $1,500 or less. Runs August 4-6.

Texas: Most clothing and footwear (excluding items used primarily for athletic activities or for protective wear) priced at less than $100 are exempt from state and local sales taxes. Accessories and clothing rentals are also excluded. Runs Aug. 4-6.

Virginia: Clothing and footwear costing $100 or less; school supplies costing $20 or less. Runs August 4-6.