Elon Musk — amping up a battle with Apple over the punishing fees it charges app developers — is reportedly planning to charge iPhone owners extra to sign up to the Twitter Blue subscription service through Apple’s App Store rather than through the web.

The Twitter boss told some of his employees that anyone who uses an iPhone to pay for the monthly subscription that grants them a blue checkmark next to their name will need to fork over $11 a month — and not the $7 is costs web users, The Information reported.

Musk had previously charged Twitter Blue subscribers $7.99 per month. At the time, the subscription service was only available through Apple’s App Store.

The iPhone upcharge appears to be over the 30% fee that Apple imposes on developers for in-app purchases. Apple would not receive a cut of Twitter Blue subscriptions that are accessed through the web.

Musk had previously suggested that he was willing to “go to war” with Apple rather than pay the commission. The Twitter boss had previously threatened to take Twitter off of the App Store after accusing the software giant of doing the same.

But Musk tweeted last week that he cleared up the misunderstanding with Apple CEO Tim Cook during a meeting at the iPhone maker’s Cupertino, Calif. headquarters.

Critics have accused Apple of unfairly using their vast market share to charge software developers the 30% commission.

It is estimated that Apple generates at least $20 billion a year through fees that it charges through its App Store.

Meta CEO Mark Zuckerberg last week hit out at Apple, saying: “Apple has sort of singled themselves out as the only company that is trying to control unilaterally what apps get on a device.”

“I don’t think that’s a sustainable or good place to be,” the Facebook founder told the New York Times DealBook summit.

The Twitter Blue service is reportedly set to relaunch on Friday, though delays are possible.

The previous rollout of Twitter Blue proved embarrassing for the social media platform after pranksters paid $8 to assume fake identities of celebrities, large companies, and other public figures — only to post unflattering messages intended to portray them in a bad light.

One Twitter user paid for a verified account and named it after the Eli Lilly pharmaceutical giant. The fake account then announced that the company was making insulin free to all customers — prompting Lilly’s stock to plunge.

Musk has indicated that the revamped Twitter Blue will include different color badges that will allow users to differentiate between government accounts, corporations, and individuals.

Twitter is also said to be working on a plan to crack down on imposters who wish to impersonate others.