An IRS processing center in Kansas City, Mo., is overdue on paying a $172.50 fee for a hazardous waste removal permit dating back to 2006.

Now the unpaid bill has been sent to the Missouri Attorney General’s Office, according to the Associated Press. The fee was for a “small quantity generator” permit, which the IRS needed to apply for when it renovated a building in order to remove and dispose of lead paint in the processing facility. Somehow the bill for the permit seems to have slipped through the cracks, though the Missouri Department of Natural Resources has notified the IRS of the nonpayment three times since 2006.

Once the IRS pays the fee, it will go toward a fund that helps pay for cleanup of hazardous waste spills. Apparently the IRS, like many taxpayers, sometimes forgets to pay its bills, though perhaps it can file for an extension.