Brian Thompson, who runs Cut Price Tomo’s TV in Middlesbrough, says he will contest the prosecution in what could become a landmark case.
He is charged with three offences against the Copyright, Designs and Patents Act, with the allegations going back to March 2015.
The kit, known as Kodi boxes, can have apps installed to allow viewers to watch copyrighted material without paying for a subscription.
Mr Thompson said selling the technology, without the apps installed, was not illegal.
He wanted the issue cleared up in court, one way or another.
He said: “All I have wanted was for it to be put in black and white.
“I sell TVs and everybody asks for boxes now.
“All I want to do is run my business and pay my taxes.
“These boxes are being sold left, right and centre. People are doing it from their bedrooms.”
The case, brought by Middlesbrough Council, will be heard at Teesside Magistrates’ Court on Tuesday.