Qualcomm claimed in federal court in California on Friday that Apple owes it $7 billion in royalties, according to a report in Bloomberg.
Apple had virtually stopped making royalty payments to Qualcomm a year ago, according to Bloomberg, as the two engaged in dozens of patent-related claims, counterclaims and fights over licensing.
Apple, meanwhile, claimed that Qualcomm was playing unfair in pricing and with its patents and licensing, according to reports.
Apple also claimed that Qualcomm - the globe's largest supplier of mobile chips - was trying get the iPhone maker to pay double for its patents - both when chips are used in iPhones and also through royalties, according to Reuters.
The dispute dates back to 2017 when Apple argued that Qualcomm was "attempting to extort" Apple over its actions with South Korean regulatory investigators, according to ZDNet.com.
Apple has used Qualcomm modems since 2011 with iPhone 4 but with its newest X phones moved away from Qualcomm to use Intel Corp. INTC, according to a report from MarketWatch last month.