Residents of European Union countries will be able to make wireless calls, use data, and send texts without any additional roaming charges when they travel anywhere in the EU as new rules take effect on June 15.

The roaming surcharges for using a mobile phone outside of one’s home country in Europe were already a small fraction of what they used to be, the result of a campaign stretching for at least a decade and strict caps put in place in April 2016. Eliminating extra charges when an EU resident moves about the bloc was, after all, one of the high-level promises of regional integration.

Telecom carriers are losing a valued stream of income, with the roaming fees representing roughly 1% to 2% of the mobile operators’ revenue and carrying high profit margins, according to estimates (paywall, link in French). Carriers with a lot of business clients will presumably see a bigger dropoff, since those customers tend to incur roaming charges more. And mobile operators in tourist-friendly southern Europe could increase their revenue (paywall, link in French), as consumers use their phones more when abroad since there are no extra fees. (The Italian and Spanish operators that the tourists connect to, for example, still get to collect wholesale fees from the tourists’ home carriers for their customers’ usage.)

The “roam like at home” rules have restrictions designed to make it difficult for consumers to shop around for a lower-priced mobile plan in another country and use it at home. Carriers can impose extra fees and limits if a consumer’s usage winds up being predominantly outside of their home countries. (Fuller details on the program and FAQs can be found here.)

One oddity of the new rules is that consumers can still pay higher fees to call outside of their home country when they are at home, though won’t face those extra charges while traveling in the country they’re calling (paywall, link in French). And it’s not guaranteed that British mobile users will benefit from the roaming rule once the UK leaves the EU—that’s subject to Brexit trade negotiations.