T-Mobile’s premium unlimited plan for four lines is now more expensive than Verizon’s—before taxes and fees, at least. So the nation’s third-largest carrier is hoping to leverage features and services to differentiate its offering from that of its biggest rival.

T-Mobile quietly ended a promotion price for its One Plus plan, raising the price from $5 a month to $10 a month in addition to the monthly fee it charges for its basic T-Mobile One plan. A single line of T-Mobile One Plus now costs $80 a month; four lines runs a total of $200 a month.

“All features are the same and we added a free Digits line,” the carrier said via email. “This is just for new or existing customers who add One Plus to their T-Mobile One plan.”

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The carrier introduced T-Mobile One last August just as Sprint unveiled a similar offering, which has sparked a war over unlimited data between the major U.S. carriers. It followed that move with the launch of T-Mobile One Plus, adding HD video and increased tethering for an additional $15 a month, then later decreased the added amount to $5 after Verizon and AT&T trotted out similar offerings.

In January T-Mobile doubled down on unlimited, scrapping its tiered plans and including taxes and fees in the monthly price.

While taxes and fees are still included in T-Mobile’s unlimited plans, the hike pits T-Mobile One Plus more directly against Verizon’s unlimited plan, which also includes HD video and mobile hotspot functionality. As BGR was among the first to notice, a single line of Verizon’s plan costs $80 a month, and four lines are available at $180 a month.

T-Mobile One Plus does offer a few perks Verizon’s unlimited plan doesn’t include, of course. In addition to Digits, which enables users to move phone numbers between devices and use multiple numbers on a single device, T-Mobile’s offering includes unlimited Gogo in-flight Wi-Fi service, for instance.

But T-Mobile has gained tremendous momentum over the last few years due in part to its willingness to undercut the price plans of Verizon and AT&T. If the price gap between T-Mobile and Verizon continues to narrow, the carrier will have to continue to develop innovative new features and service models to maintain that momentum.