T-Mobile on Wednesday made its next big move to shake up the wireless world by announcing a new cheap $40 wireless plan that offered unlimited voice and text along with 500MB of LTE data per month. The big selling point of this new plan is that, unlike Verizon and AT&T, T-Mobile won’t charge you any data overage fees if you go over your monthly allotment. However, there’s a big asterisk here that anyone who’s interested in subscribing to the plan should know about before taking the plunge.

Unlike other capped T-Mobile plans that throttle your data connection down to 2G speeds if you exceed your monthly limit, this new plan implements a hard data cap so that if you go over 500MB of LTE data in a given month, you’ll be cut off from mobile data — period. T-Mobile says that if you run out of data on this plan and want to buy more before the start of the next month, you can buy a one-day pass that will give 500MB of new LTE data on the network for $5 or a one-week pass that will give you 1GB for $10.

We bring this up because T-Mobile hasn’t yet made this explicitly clear anywhere on its Simple Starter promotion website. Earlier in the day, the website said that T-Mobile would throttle your speeds down to 2G if you exceeded your cap, although this claim has now been removed. It’s entirely possible that T-Mobile is planning to update the page with the correct information on what happens if you go over your monthly allotment shortly.

Prior to joining BGR as News Editor, Brad Reed spent five years covering the wireless industry for Network World. His first smartphone was a BlackBerry but he has since become a loyal Android user.