On forms like the W-2, the IRS explicitly tells you to avoid using staples to attach documents or checks (“Staple holes or tears interfere with machine reading.”) The 1040, meanwhile, requests that you attach documents and other miscellaneous sheets of paper, but cordons off areas where staples are not allowed.

Missing in the IRS’s language of rules and regulations is the word “paperclip,” meaning one can assume these mini metal tools are fair game. If even just a small fraction of taxpayers follow this train of thought, then the IRS becomes the proud owner of a huge batch of new paperclips each year. So, what do they do with the influx of office supplies?

The agency doesn't keep track of exactly how many paperclips are sent in with people's forms, but they try to make sure they don't go to waste. “When we receive paperclips attached to paper returns, we simply re-use them,” says an IRS representative. “There’s no need for paperclips if taxpayers E-File, which the majority of people do,” he adds, meaning the stream of free paperclips is quickly coming to an end.

The IRS’s filing statistics state that of the around 149,684,000 individual income tax returns they received in 2014, 125,821,000 were e-filed, a three percent increase from 2013. At this rate, the days of free paperclips for the IRS are numbered.