Microsoft has opened up a lawsuit against Samsung, claiming the Korean manufacturer owes the PC manufacturer $6.9m (4.3m) for interest on late payments.
Samsung and Microsoft have two agreements in place with Microsoft, a cross-licensing agreement and a business collaboration agreement, with the latter stating Samsung will promote its Windows smartphones and tablets.
Although Samsung has already forked out roughly $1bn (62.5m) a year in royalty payments for the use of the Android platform, it stopped paying last year because it felt Microsoft had broken the original business collaboration agreement when it bought Nokia.
However, the two companies worked it out and Samsung began paying its dues again, but without the interest Microsoft charged.
Now, Microsoft is going after that money via a New York federal court where it filed the lawsuit in August.
Deputy General Counsel representing Microsoft David Howard said: "We are confident that our case is strong and that we will be successful. At the same time, Microsoft values and respects our long partnership with Samsung, is committed to it, and expects it to continue."
Microsoft began charging manufacturers for using Android, despite it belonging to Google, because the Windows maker believes the smartphone platform uses some of its technology. The company hasn't, however, specified which parts of Android uses Microsoft's tech.
Motorola is the only manufacturer using Android that refuses to pay for the use of the software because it thought the demands were unfair and it hadn't infringed any of the patents Microsoft listed.
