DUXBURY (CBS) — “It doesn’t hold much” — which is clear to see as Jeannie Martin opened up a container behind her house. “I paid $49.95 for that, on sale, at Benny’s back in 2000.” It’s a plastic box barely big enough to hold a lawnmower, a camping cot, a stroller, and some windshield washer fluid.

Jeannie recently discovered she has been paying real estate taxes on the box for the past 9 years. “I was rather shocked.”

Duxbury town records show the 18-year-old, $50 dollar plastic box listed as a 30 square foot shed assessed for $300.

“I did not know there was an itemized list. I just paid my taxes like a good citizen.” It wasn’t until Jeannie questioned a sharp increase in her tax bill and went to town hall that she saw the itemized list. That’s when Jeannie noticed she was being taxed on an “outbuilding” that doesn’t exist. “The town said to me that – yes they made a mistake, yes this is not an outbuilding. But it’s your responsibility.”

When WBZ-TV called the Duxbury Tax Assessor, he was able to remove the “outbuilding” from the assessment. And while the mix-up only cost Jeannie a few extra dollars a year she’s still not happy the backyard box ever wound up on her tax bill. “The fault is on me but I also think this is a big mistake.”

Duxbury’s Tax Assessor told us that January is the month to check your bill and to ask the town to make any necessary corrections. Most itemized real estate bills can easily be found on your town’s website if you want to check it out.