Vodafone has been selling Apple's iPhone in the United Kingdom for only a week and has managed to sell 100,000 units already. O2 lost its deal as the exclusive iPhone carrier in the U.K. last year, and Vodafone had been planning an early 2010 iPhone launch of its own.
The company said on Twitter on Friday, "Just over a week since launch and @VodafoneUK has already sold its 100,000th iPhone!"
Other carriers competing for iPhone customers in the U.K. include Orange and Tesco Mobile, chipping away at O2's potential subscriber base even more.
Vodafone began selling the iPhone on January 14, and managed to hit the 50,000 unit mark by the end of the day.