T-Mobile/ZDNETAn advertiser paid for editorial consideration of this deal. Our editorial experts vetted the deal using their independent expertise. Because we determined that the deal will save money for the consumer, we wrote the content.T-Mobile Fiber delivers 100% fiber internet to your home, with unlimited data and plans starting at $45 per month with AutoPay. Right now, new customers who sign up for the 1 Gig or 2 Gig plan will get their first month on T-Mobile, while 2 Gig customers also get $100 back via a virtual prepaid Mastercard, for a limited time.Also: The right way to run an internet speed testThe month on T-Mobile applies to both the 1 Gig plan, which runs $60 per month with AutoPay, and the 2 Gig plan at $70 per month, so you don't have to max out your speeds to qualify. The offer isn't applicable to the entry-level 300 Mbps, though. After your first 30 days, the plan automatically renews at the regular rate ($70 per month for 1 Gig, $80 per month for 2 Gig), plus taxes and fees, and the AutoPay discount brings that back down by $10. The offer requires a new fiber internet line rather than a brand-new T-Mobile account, so if you already have a T-Mobile phone plan, you can still get in on it.Also: Fiber vs. cable: Understanding the differencesSince this is a full-fiber connection rather than cable, your upload speeds keep up with your download speeds, which you'll appreciate for video calls and cloud backups. Professional installation and equipment are included, meaning there's no gateway to buy or install fee you need to budget for. T-Mobile/ZDNETAs for the $100, it arrives as a virtual prepaid Mastercard, and T-Mobile says to allow 14 weeks from rebate submission for it to show up. The card is only good for 6 months after it's issued, so make sure you use it up before then. You should also plan on keeping the service for a while, because the full value gets charged back if you cancel within 180 days of installation, and half of it if you cancel within the first year.Note: The AutoPay pricing needs a bank account or debit card, otherwise you'll pay $10 more each month, and the equipment has to go back undamaged if you cancel, or a fee may apply. T-Mobile Fiber isn't available in all areas either, and pricing can vary by address. You should punch in your address on the T-Mobile Fiber site first to see what you're working with.Looking for the next best product? Get expert reviews and editor favorites with ZDNET Recommends.How I rated this dealI've seen a bunch of fiber deals over the last few years, and this one holds up well. A month of fiber on T-Mobile plus $100 back works out to around $180 in value across your first year on the 2 Gig plan. The strings here are the 14-week wait for the card and the chargebacks if you cancel within the first year, though if you're planning to stick around anyway, neither of those should bother you much. Similar card offers pop up at other big fiber providers often enough, but their 2 Gig plans cost anywhere from $100 to upwards of $150 a month, which makes this one a better deal. That's why I gave this deal a 4/5 Editor's deal rating. T-Mobile says it is running this promo for a short window, so we recommend jumping on it while you can. Deals can expire or change without warning, but our team keeps a close eye on everything we post to make sure it actually works. If you happened to miss out this time, don't worry. We're always hunting down fresh ways to save you money over at ZDNET.com.