NEWCASTLE

The U.S. Postal Service won't give Newcastle its own ZIP code, and Mayor Sonny Putter says that decision is hurting the city treasury.

Newcastle's sales-tax collections are running short because the city shares ZIP codes 98056 and 98059 with Renton, and some mixed-up business owners are designating their tax receipts for Renton when they mail payments to the state. The two ZIP codes, which are used primarily for Renton, were established before Newcastle became a city in 1994.

It's more than a matter of civic pride, the mayor said.

"We are losing money because of the Postal Service's intransigence," said Putter, a certified public accountant. "For us, this is a major problem."

Newcastle, a city of 8,645 people, doesn't qualify for its own ZIP code because the area isn't crowded enough to need one.

"The ZIP-code structure is not to create community identity. It was created for the distribution of mail," said Steve Dearing, Seattle-area address manager for the Postal Service. The existing codes in Newcastle are used at half their capacity, and people are getting accurate mail service, so there's no reason to change, he said.

However, City Manager Andy Takata said Monday that Newcastle is studying its legal options.

The state requires businesses to identify cities on forms they mail to Olympia with their payments. Mistakes happen.

"It's a perennial problem," said Mike Gowrylow, spokesman for the state Department of Revenue.

The city has no idea how much money it should have received. A consultant is trying to figure that out.

One of the city's largest taxpayers, a Safeway store on Coal Creek Parkway Southeast, sent taxes to Renton between November and May, causing a dip in Newcastle's revenues. Takata said the city didn't spot the problem for seven months because his staff is too small to conduct monthly audits. Putter discovered the missing Safeway payments.

Recently, Newcastle got that money back, said Rob Hendrickson, city finance director. But it may be tougher to recoup lost taxes from smaller or lesser-known firms.

A separate but related problem appears on the Revenue Department's Web site, where an "address search" feature for taxpayers says Newcastle's two shopping centers are in Bellevue. A spokesman said the Web site will be fixed this month.

Taxpayers might be forgiven if they're confused. King County has 664 taxing districts, many with overlapping borders and multiple ZIP codes. Keeping track is especially hard for firms such as land scapers and contractors who move between locations, and for out-of-state companies doing business in Washington.

Putter calls ZIP codes universal identifiers, like Social Security numbers, and says by giving Newcastle its own code, the Postal Service would help local governments be more efficient.

But even if Newcastle prevails, a new code might cause hassles. Kenmore, which incorporated two years ago, obtained a single 98028 ZIP code after being split in three, and some residents failed to submit needed change-of-address forms. After a year, those people quit getting some mail, including their property-tax notices, said Assistant City Manager Carter Hawley.

"It was the biggest headache," she said.

Mike Lindblom's phone message number is 206-515-5631. His e-mail address is mlindblom@seattletimes.com.