The Essential Phone is designed to work on all four major US mobile networks: Verizon, AT&T, T-Mobile, and Sprint. It has the necessary technology inside for compatibility with each. So the $699 debut device from Andy Rubin’s new company, at minimum, should be able to place calls, send texts, and use wireless data. The core smartphone functions are there. Essential’s own support page confirms wide support, pledging that “unlocked Essential Phones bought on Essential.com will work with any carrier.”

But the story might be different for “advanced network” features like HD voice, built-in video calling, and so on. Carriers aren’t yet revealing just how well the Essential Phone will work on each of their networks. Performance might not match the network-certified smartphones you’ll find on their retail shelves — and some specific, network-dependent functions might be absent. The Verge has reached out to all four major US wireless providers for comment on what buyers of the Essential Phone can expect when the device ships later this year. AT&T has yet to respond, but I’ll update this story once the company has.

Verizon: ¯\_(ツ)_/¯

Verizon initially provided The Verge with this emailed statement on Tuesday: “While the phone might work on Verizon, we can't promise the same experience and quality of service as devices that have been tested and approved for use on our network.” When asked whether Verizon plans to sell Essential’s Phone directly, the company declined to comment on its retail pipeline.

On Wednesday, a Verizon spokesperson confirmed that Essential is in fact working alongside Verizon to fully certify Phone for compatibility with the largest US carrier’s network.

AT&T: If it’s compatible, it’ll work.

“We have been and continue to be open to any customer bringing compatible devices to our network. We will be able to comment more on the level of compatibility at the phone's launch.”

T-Mobile: It will work, but some advanced features might not be available.

T-Mobile was quick to confirm that the Essential Phone will be supported on its network, but it sounds like the Uncarrier won’t be selling it direct. “We’re excited for Andy Rubin and his team (the device looks amazing), and welcome customers purchasing Essential to bring it to the fastest and most advanced 4G LTE network in the country through our BYOD program. We’ll have more to share closer to general availability in terms of what advanced network features might be available in Essential.” That mention of the company’s bring-your-own-device policy suggests that T-Mobile isn’t planning to offer the device in its stores.

Sprint: Yes, it will work.

A Sprint spokesperson confirmed via email that “Essential’s debut smartphone will operate on our network. More specific information will be provided at a later date.”

Essential is telling many users on Twitter that it’s working hard to make the Phone more widely available. That said, executives also told Wired that the company really isn’t set up to mass produce the Phone at iPhone or Galaxy-type scale. Churning out phones made from titanium and ceramic isn’t easy for a young company, it turns out.

Universal carrier support is still rare to find in many phones. The OnePlus 3T, another popular Android device that’s not sold by US carriers, works on AT&T and T-Mobile — but not Verizon or Sprint. But others like the iPhone, LG G6, and Motorola G5 can be purchased unlocked and work across all four big providers.