US phone operator Verizon has invested $400,000 in US-based mobile phone services company CardStar as part of a $1.4m series A round, according to news provider Wall Street Journal.
The A round had initially been closed in March at $1m from Acta Wireless, a consulting and seed investment group, and two early-stage venture capital firms Amplifier Ventures and LaunchCapital before Verizon Ventures joined earlier this month.