VoIP calling outfit Rebtel launches a challenger to Twilio called Sinch

Over the last seven years Rebtel has building a global communications network to offer its customers cheap international VoIP and IP messaging services. Now the Swedish over-the-top calling company plans to start offering that network to developers and even potential competitors that want to add voice, messaging and chat services to their smartphone apps.

In short, Rebtel wants to create a communications API company in the same vein as Twilio, Nexmo, Layer and Tyntec. On Wednesday, Rebtel and its investors Index Ventures and Balderton Capital announced the creation of a new independent company called Sinch, infusing it with $12 million in funding and transferring most of Rebtel’s physical communications infrastructure and many of its employees to the new entity.

Rebtel's tablet apps (source: Rebtel)

Rebtel’s tablet apps (source: Rebtel)

As with Twilio’s model, Sinch will offer cloud APIs to developers that they can use to add voice, SMS and messaging features to their apps with a few lines of code. Sinch’s infrastructure will then route and terminate their conversations regardless of whether their final destination is a smartphone app, an SMS client or a landline telephone.

For instance, if you’re a startup building the next ridesharing service, you could tap Sinch’s APIs to generate the “driver has arrived” SMS notifications to the rider’s phone or, if the driver and rider can’t find one another, instantly set up a phone call between them. Another example would be a gaming mobile company that wants to set up two-way “trash talking” channels between gamers on a multiplayer platform.

Rebtel started down this path in 2012 when it launched an SDK that allowed developers to integrate its VoIP services into its apps. But with the launch of Sinch, the company appears to be getting far more serious about growing the communications outsourcing aspect of its business.

MOBILIZE 2010: Andreas Bernstrom – CEO, Rebtel

Andreas Bernström speaking at Gigaom Mobilize 2010 (Source: Gigaom)

Sinch will be an independent company and Rebtel will essentially become one of its customers, allowing it to scale far beyond Rebtel’s core user base of 25 million international calling customers, said Andreas Bernström, Rebtel’s current CEO who will take over the helm of Sinch. Though the communications space is growing more and more crowded with API companies, Bernström said Sinch would have a few advantages.

First, Sinch will have a lot of experience in building over-the-top communications services after seven years of building Rebtel, making it a good fit for any mobile developer, Bernström said. Second, it’s already developed extensive relationships with the carriers that will terminate its developer customers’ calls and texts. Bernström said it could offer far cheaper rates than Twilio, Nexmo or any other competitor.

Rebtel was one of the first global over-the-top communications companies, though it has always lived in Skype’s(s msft) shadow. Unlike the newer breed of OTT companies like WhatsApp and WeChat, it has focused less on building up a massive consumer customer base and more on monetizing communications among a much smaller following of expats and globetrotters. Lately, though, it’s been branching out into new businesses. In December, Rebtel spun out Sendly, a kind of international money transfer service that uses prepaid voice minutes as currency.