Michael Ratcliffe never thought his career as a geographer would help him with his tax returns.
But when he got a letter in May notifying him that his state income tax refund was being reduced from $294.12 to $59.72, he was fairly certain there had been a geographical mistake.
Mr. Ratcliffe, a geographer with the Census Bureau in Suitland, lives in the Howard County portion of Laurel, known unofficially as North Laurel.
But in the eyes of the state comptroller's office, he's a Prince George's County resident because of his Laurel mailing address.
As in real estate, location is everything when it comes to the piggyback tax. Set at 60 percent of the state rate in Prince George's and 50 percent in Howard, the difference could have cost Mr. Ratcliffe $234.40.
Operating under the assumption that Mr. Ratcliffe lived in Prince George's, state income tax officials reduced his refund to reflect the difference in the county's tax rates.
"As soon as I saw the revision, I had a pretty good idea of what had happened," said Mr. Ratcliffe, who wrote a letter to the income tax division of the state comptroller's office explaining the problem.
The income tax division sent him a letter last week saying the office would respond to his inquiry soon.
The confusion over Mr. Ratcliffe's place of residence raises another question -- for the two years he's lived in Howard County, has the local share of his state taxes gone to Prince George's County?
"If they get the county wrong are they allocating my taxes to the incorrect county?" Mr. Ratcliffe asked.
From a taxpayer's standpoint, it would have been impossible to know of the mistake, because Howard and Prince George's had the same 50 percent piggyback tax rate until the General Assembly approved legislation last year allowing the counties to raise the rate to 60 percent.
Mr. Ratcliffe is wondering if the same thing has happened to others living in the Howard section of Laurel.
"For anybody who moved from Prince George's to Howard in the last few years, this definitely could have happened," Mr. Ratcliffe said. "We wondered if others had received the wrong refund and just assumed they made a mistake."
George H. Spriggs Jr., deputy director of the state income tax division, said he believes Mr. Ratcliffe's case is an isolated incident. "It's difficult where you have these split jurisdictions where one street can be in two different counties," he said. "As soon as somebody lets us know we have the incorrect subdivision, we make the correction."
Mr. Spriggs said he's heard of a few similar cases in areas near the Baltimore County and city lines, but he's not aware of other instances in the Laurel area.
Del. Martin G. Madden of District 13B said he and Sen. Thomas M. Yeager of District 13 spoke with Mr. Spriggs about the mix-up and asked him to do a computer check to determine if the problem is widespread in the Laurel area.
Mr. Spriggs said the comptroller's office is installing a new computer system to ensure that county codes correspond with street addresses.
As a geographer, Mr. Ratcliffe was well aware of the potential for such a mix-up.
In fact, he had recently discussed the topic of postal addresses that cross county lines with a colleague at work who is researching the subject.
And in another coincidence, shortly after he received the revision notice from the state comptroller, Mr. Ratcliffe presented a paper, titled "Statistical Geography of Howard County," at the meeting of the Mid-Atlantic Division of the Association for American Geographers.
"The whole thing has been quite humorous; of all people for it to happen to," he said. "It gave me an interesting anecdote for my paper."
The confusion stems from the preprinted label that Mr. Ratcliffe attached to his return. The county code on the label corresponded to Prince George's County.
Apparently, when Mr. Ratcliffe moved from the Prince George's section of Laurel two years ago, it wasn't noted in state income tax records that his county of residence had changed because he still had a Laurel postal address.
As a postal area, Laurel extends into four counties -- Howard, Prince George's, Montgomery and Anne Arundel -- with four ZIP codes serving the area.
"They assumed that since the city of Laurel is in Prince George's County, all Laurel addresses are in Prince George's County," Mr. Ratcliffe said.
Confusion in communities that include more than one political jurisdiction are fairly common, he said, particularly for the delivery of emergency medical services in rural areas.
"Data bases sorted on ZIP codes don't give you a direct correlation between political geography and postal geography," he said.