The Last Big Internet Data Cap Is Living on Borrowed Time — Cox, Xfinity, AT&T and Who Still Charges Overages in 2026

Updated on September 15, 2026

By Christopher Burg · Last updated September 10, 2026

An internet data cap is the fee your bill never advertises. As of September 10, 2026, Cox is the last major cable provider still charging overage fees on a 1.25 TB cap, Xfinity’s 1.2 TB internet data cap now applies only to legacy plans, and AT&T caps its copper plans at 1.5 TB. Every big fiber network, Spectrum, Optimum and the 5G home carriers sell unlimited data. And Cox’s cap is living on borrowed time: Spectrum, which doesn’t cap anyone, closed its purchase of Cox on August 20 and says its full lineup launches in Cox markets in mid-September.

What is an internet data cap?

An internet data cap, sometimes called a data plan or data allowance, is a monthly limit on how much data your home plan includes, measured in gigabytes (GB) or terabytes (TB). Everything you stream, download, upload, back up or video-call counts toward it. Go over and one of three things happens depending on the provider: you’re billed for extra data in blocks, you’re pushed toward an unlimited add-on, or your speeds are slowed until the next billing cycle.

Cable networks tend to use hard caps with per-block overage charges. Satellite providers sell “priority data” buckets and slow you afterward. Fixed-wireless 5G plans have no hard cap at all but can deprioritize your traffic.

Which providers still have an internet data cap in September 2026?

The short version: the internet data cap has retreated to three places — Cox’s cable footprint, Xfinity’s legacy plans, and AT&T’s copper network — plus satellite, where it takes the form of priority-data buckets. Here is the provider-by-provider status, verified against each company’s own policy pages where they publish one.

Sources: Cox “Speeds and Data Plans” policy (updated Feb 24, 2026), Xfinity 1.2 TB data plan FAQ, AT&T data allowance support article, CableTV.com data cap guide (Apr 15, 2026) for the Cox unlimited price and the Mediacom/Sparklight/Astound rows.

Cox: the last big internet data cap, and why the Spectrum deal matters

Cox is the only large cable operator that still bills overages. Its policy page, updated February 24, 2026, lists the same 1.25 TB monthly data plan on every wired tier from Fast 300 Mbps to Go Beyond Fast 2 Gig, with overages at $10 per 50 GB block up to $100 a month ($30 for ConnectAssist customers). Cox credits the first overage in a customer’s history, sends usage alerts starting at 50%, and doesn’t count Cox phone service or most Contour video toward the cap. Two quiet exceptions: plans delivered over Cox’s wireless network and the prepaid StraightUp Internet product carry the same 1.25 TB allowance but “Not Applicable” overage charges.

What changed is the owner. Charter, which runs Spectrum, completed its acquisition of Cox on August 20, 2026, and Spectrum has never enforced a data cap. Charter’s closing announcement says Spectrum plans to launch its entire product suite to consumers in the former Cox markets in mid-September, while telling existing customers they will “not see any pricing or service changes at this time, unless initiated by you.” Read those two sentences together and the picture is this: a Cox customer who moves to a Spectrum plan when the lineup arrives leaves the cap behind; a customer who stays on a legacy Cox plan keeps it until Charter says otherwise. Neither company has announced a date for retiring the Cox cap outright. If you’re a Cox customer who regularly clears 1 TB, the mid-September plan launch is the moment to compare, and our Charter–Cox merger guide tracks what’s changing month by month.

Xfinity: unlimited on new plans, 1.2 TB on legacy plans, and the 13 states that never had a cap

Comcast’s own support page is unusually plain about it: “New Xfinity Internet plans include unlimited data and equipment at no extra cost. The 1.2 TB data limit only applies to older (legacy) internet plans.” If you’re still on a legacy plan, the first time you exceed 1.2 TB in a 12-month period is a courtesy month with no charge; after that it’s $10 per 50 GB up to $100. Alerts arrive at 75%, 90% and 100%, and again when overages hit $50 and $100. You can’t opt out of the legacy cap, but you can escape it three ways: switch to any new plan at 300 Mbps or above, add Unlimited Data, or add xFi Complete where it’s offered.

The exclusion list is worth knowing. The 1.2 TB cap never applied to Xfinity customers in Connecticut, Delaware, Massachusetts, Maryland, Maine, New Hampshire, New Jersey, New York, Pennsylvania, Virginia, Vermont, West Virginia and Washington, D.C., plus parts of North Carolina and Ohio — the old NBCUniversal/Northeast footprint. It also never applied to Internet Essentials, Prepaid, NOW Internet or Gigabit x10. Xfinity’s page notes most of its customers use about 498 GB a month. If you’re on a legacy plan, our Xfinity speed-tier guide shows what the current no-cap plans cost.

How much do overage fees actually cost?

On a capped cable plan, every overage is billed in 50 GB blocks at $10 each, up to a $100 monthly ceiling. That ceiling is the number to remember: a $60 plan can become a $160 plan in a heavy month, and AT&T DSL’s ceiling is $200. The unlimited add-ons that avoid the risk cost $30 a month at AT&T and Xfinity legacy plans, and about $50 at Cox, which means a capped customer paying for unlimited is often paying more than an uncapped fiber or 5G plan at the same address would cost outright.

Those numbers explain why the cap became a retail problem for cable operators. An average home is now using more than half of a 1.2 TB allowance every month, and the 2 TB club is growing at double digits. Homes that work from home with cloud backups, run several 4K streams, or download games in the 100 GB range are the ones that hit overages, and they’re exactly the customers a provider least wants to lose to fiber.

How do I know if I’m hitting my internet data cap?

Every provider with a cap runs a usage meter. Cox shows it under Internet Tools in the Cox app; Xfinity shows it to primary or manager users in the Xfinity app; AT&T shows it in myAT&T. Check it twice in a billing cycle, at the midpoint and three days before the reset, and you’ll know whether your household is a 400 GB home or a 1.4 TB home. For a rough forecast, Netflix publishes that 4K streaming uses up to 7 GB an hour and HD about 3 GB an hour; three hours of 4K a night is roughly 630 GB a month on its own before anyone downloads a game, backs up a phone, or joins a video call.

How to avoid internet data caps and overage fees

The surest way to avoid a cap is to pick an uncapped plan in the first place, and in 2026 that’s most of the market. If you’re already on a capped plan, work through these in order:

1. Check whether you’re on a legacy plan. Xfinity customers on a cap can move to any current plan at 300 Mbps or above and the cap disappears. Cox customers should watch the mid-September Spectrum lineup for the same reason.
2. Compare uncapped providers at your address. If AT&T Fiber, Frontier, Fios, Google Fiber, Quantum, Spectrum, Optimum or a 5G home carrier serves you, the cap question is over. Our guide to fiber vs. cable vs. 5G home internet covers the tradeoffs.
3. Price the unlimited add-on against a switch. Cox’s roughly $50 add-on and AT&T’s $30 add-on are, in most markets, more than the gap between your plan and a competitor’s uncapped one.
4. Use the courtesy month deliberately. Xfinity legacy plans forgive one overage per 12 months; Cox credits your first ever. If a big move or a new console is coming, schedule the heavy month.
5. Trim the invisible usage. Set streaming apps to “auto” or 1080p on TVs that aren’t 4K, turn off automatic cloud backup of video, and pause console auto-updates. Those three settings are the difference between 900 GB and 1.3 TB in a lot of homes.

Is anyone going to ban the internet data cap?

Not soon. The FCC opened a formal Notice of Inquiry into broadband data caps in October 2024 (WC Docket No. 23-199) to study how caps affect consumers and competition. Industry groups asked the agency to drop it, an inquiry gathers information rather than making rules, and the commission that opened it changed leadership in January 2025. As of September 2026 no rule has followed, and the FCC’s public “data caps” consumer page now returns a notice that access has been disabled. In practice, the data cap is being retired by competition, not regulation: fiber overbuilders and 5G home internet sell unlimited data as a headline feature, and the two cable companies that held out longest, Comcast and now Cox through Charter, are the ones giving way.

Frequently asked questions

Sources

• Cox — Speeds and Data Plans Information for Internet Services (updated February 24, 2026)
• Xfinity — Xfinity Internet 1.2 TB data plan FAQs
• AT&T — Home internet data allowances
• Charter — Charter and Cox Communications Complete Transaction (August 20, 2026)
• OpenVault — Broadband Insights Report (OVBI) 2Q26 (July 22, 2026)
• FCC — FCC Explores How Broadband Data Caps Impact Competition and Consumers (Notice of Inquiry, October 2024)
• CableTV.com — Internet Provider Data Caps Guide (April 15, 2026)

Keep going

• Charter–Cox merger: what it means for customers
• Xfinity internet speed tiers and what they cost
• Fiber vs. cable vs. 5G home internet
• Best 5G home internet plans
• How to lower your internet bill without canceling
• Best cheap internet plans
• Sparklight internet: the $40 gig that becomes a $95 bill