The U.K.’s antitrust regulator has greenlighted the longstanding planned merger between two of the country’s biggest telecommunication operators.

Vodafone and Three constitute two of the U.K.’s four infrastructure-owning mobile network operators (MNOs), alongside O2 and EE. As such, when the duo revealed plans to merge in a $19 billion transaction last June, it was always likely to attract scrutiny. As such, the Competition and Markets Authority (CMA) kicked off its initial “phase 1” probe in January, before progressing things to a full in-depth investigation in June, after conducting a market analysis and collating industry feedback.

Then in September, the CMA delivered its provisional findings, concluding that the merger could lead to higher prices for consumers, diminished services, and reduced investment in U.K. mobile networks. But it stopped short of blocking the deal, instead suggesting potential remedies to appease its concerns.

And this leads us to today, with the CMA finally giving approving the deal — with conditions. It said both companies must sign binding commitments to “invest billions” to launch a combined 5G network across the whole U.K. In the shorter term, the CMA also said that the new combined entity would have to cap “certain mobile tariffs” for three years, while mobile virtual network operators (MVNOs) would also continue to have pre-set contractual terms for the same period. customer protections which would require the merged company to cap certain mobile tariffs and offer preset contractual terms to mobile virtual network operators, for a period of 3 years.

These commitments will be overseen by the CMA and Ofcom, the U.K.’s regulatory and competition authority for the telecommunications industry.

“It’s crucial this merger doesn’t harm competition, which is why we’ve spent time considering how it could impact the telecoms market,” Stuart McIntosh, chair of the CMA’s inquiry committee said in a statement. “Having carefully considered the evidence, as well as the extensive feedback we have received, we believe the merger is likely to boost competition in the U.K. mobile sector and should be allowed to proceed — but only if Vodafone and Three agree to implement our proposed measures.”