Six-figure ZIP codes

It pays to live in Carlisle or Harvard.

These enclaves of small-town New England top the list of wealthy ZIP codes northwest of Boston, according to a Globe analysis of income-tax filers with incomes of $100,000 or more.

As taxpayers race to file their returns by Tuesday, it's worth knowing this: Not all ZIP codes are created equal. Some are wealthier than others, sometimes much wealthier.

The Globe examined Internal Revenue Service data for the 2004 tax year, the most recent available, to see how filings compared from ZIP code to ZIP code and community to community.

In Carlisle and Harvard, 45 and 41 percent of tax returns, respectively, reported income of more than $100,000. Each town is covered by a single ZIP code, 01741 for Carlisle and 01451 for Harvard.

Twelve ZIPs were in the 30 percent range: Lexington (02421), 38 percent; Belmont (02178), 37 (outdated zip code in limited use); Lexington (02420), 37; Concord (01742), 36; Winchester (01890), 36; Westford (01886), 36; Andover (01810), 34; Acton (01720), 34; Groton (01450) 33; Boxborough (01719), 32; Acton (01718), 31; and Bedford (01730), 30.

The lowest percentage in the region came from two Lawrence ZIP codes, 01840 and 01841, where 1 percent of filers earned more than $100,000 in tax year 2004.

Overall, the area had 18 percent of its filers earning more than $100,000, compared with a statewide average of 14 percent for 2004.

In Greater Boston, the highest was 47 percent, in the 02110 ZIP code that covers parts of Boston's Financial District and waterfront.

The data used what the IRS calls "adjusted gross income," which includes some deductions, such as IRAs and interest on student loans. Joint and single filers are included, so married couples filing jointly count as one filer. Statewide, the average filer's adjusted gross income in 2004 was about $63,000.

The IRS does not cite ZIPs where fewer than 10 filers earned more than $100,000, nor does it disclose areas where the percentage is above a certain number, although it does not reveal what that number is.

All of those high-earning filers in area communities may not translate into an IRS bonanza, however, considering the creative loopholes that taxpayers, or their tax preparers, have found to limit the next big number on their returns: taxable income.

Sometimes, though, preparers spend a lot of time persuading clients what not to try to deduct.

Many homeowners are convinced that they can deduct the cost of pricey home renovations, such as new kitchens, said Cindy Brandt of C.A. Brandt & Associates, which has offices in Cambridge, Woburn, and Haverhill.

Wrong.

"I tell them, that's nice, but it doesn't help with taxes," Brandt said.

One business owner recently tried to deduct a $4,100 tab for 22 people at a pricey restaurant, but Brandt wouldn't let her.

"Those are red flags" for the IRS, which looks closely at travel and entertainment expenses, she said.

Sometimes honest people regret just how honest they were.

Girard Healy of Wakefield, a CPA with Beacon Consulting Group in Boston, tells the story of Ermenegildo Cesarini and his family, who discovered a cache of about $4,500 in a piano they had owned for seven years.

They dutifully declared the income to the IRS and paid the taxes, Healy said.

Then perhaps regretting their decision, they decided to fight the IRS and launched a 13-year battle to get their tax money back.

In the end, the family lost. The IRS declared that taxes have to be paid on found money.

About 3.1 million returns will be filed in the state this year, predicted Peggy Riley, the IRS spokeswoman for New England.

Of those, about 70 percent will get refunds. About 1.8 million returns will be filed electronically.

And how many procrastinators will miss the Tuesday filing date and need an extension? About 181,000.

So get to work on those forms.

Matt Carroll can be reached at mcarroll@globe.com.