Previously accessible by invite-only, Google’s virtual mobile network Project Fi is now open to anyone in the U.S. To celebrate the general availability of Project Fi, Google is even throwing in a discount offer for all Project Fi users on its new Nexus 5X Android smartphone.

Introduced in April 2015, Project Fi offers users a cellular (local voice and local/international text) and data plan using Sprint and T-Mobile towers. Users are billed only for actual data used (per MB) and credited for any unused data.

Although technically open to anyone in the U.S., there are a few requirements you have to meet to sign up for Project Fi.

What you need to use Google’s Project Fi

1. A U.S.-based Gmail account — although Project Fi offers coverage in 120+ countries, the service is only open to subscribers in the U.S.
2. Reside is a supported service area — Google will let you check during the signup process or you can check at https://fi.google.com/coverage.
3. A recent Nexus device — the Nexus 6, Nexus 6P, and Nexus 5X are the only supported devices. If you do not already have one of these devices you can order a 16GB Nexus 5X at a discounted price of $199 (limited time offer in conjunction with Project Fi’s general availability) or you can get a 32GB Nexus 6P for $499.
4. Project Fi does not require an annual contract or commitment, but if you want to finance your device purchase (over 24 months), your application will be subject to a credit check (check terms and conditions here).

How to sign up for Google’s Project Fi

If you meet all the requirement to use Project Fi, here’s how to sign up:

1. Go to the Project Fi sign up page.
2. Sign in with your Gmail account details and follow the onscreen prompts, including: entering your ZIP code; service address, picking a new phone number (or entering the relevant information to port an existing number to Project Fi); selecting your wireless plan; ordering your Project Fi SIM card and/or a Nexus device if you do not already own one.
3. Your Project Fi SIM and/or device will arrive along with a welcome kit that includes instructions on how to activate your Project Fi service.

How to select a data budget for Project Fi and how you are charged

Fi Basics, Project Fi’s “simple plan”, costs $20 per month and includes unlimited domestic talk and text, unlimited international texts, Wi-Fi tethering (so you can use your mobile as a hotspot), and cellular coverage in more than 120 countries.

Part of the signup process is picking a data budget (or wireless plan). Google recommends that you set your Project Fi data budget based on your past data usage (although it’s worth noting that on average Project Fi users use about 1.6GB of data per months, according to Google).

You can adjust your data budget on a month-to-month basis if you don’t quite get it right the first time or if there are months when you need more (or less) data than usual.

Watch Google’s handy video below to learn how to check your monthly data usage:

If at the end of the month, you’ve used less data than you picked in your data budget, Google will give you a credit at approximately one cent per MB of unused data towards your next month’s bill, effectively lower your bill.

If you’re about to go over your data budget, Project Fi will alert you and if you do go over you’ll continue to get full-speed data at the same $10 per GB as the basic plan.

Sources: Android Blog; Project Fi

Image credit: freestocks.org, Flickr