Meta has unveiled plans to introduce adverts on WhatsApp, breaking a promise by the messaging app’s co-founder never to do so.

In a major update announced on Monday, WhatsApp said it will roll out paid advertising to its 3bn monthly users over the next few months.

The move is in direct violation of the “no ads, no games, no gimmicks” pledge made by Meta following its $19bn (£14bn) acquisition of WhatsApp in 2014.

Jan Koum, WhatsApp’s co-founder and chief executive at the time, had the mantra written on a note taped to his desk.

In a 2012 blog post entitled “Why we don’t sell ads”, he wrote: “Remember, when advertising is involved you the user are the product.”

The decision to abandon this promise risks fuelling concerns that the app is becoming more of a social media platform instead of a messaging service.

It also comes after Meta began rolling out its own artificial intelligence (AI) function within WhatsApp, allowing users to interact with a chatbot similar to ChatGPT.

Meta AI also offers AI-powered search suggestions.

The new AI feature, which cannot be deactivated or deleted, has prompted a furious backlash from some users who branded it “bug-ridden rubbish”.

Despite this, Meta has said it will add further AI features, including writing suggestions and summaries.

The new features will allow all businesses to promote their channels to WhatsApp users, as well as to run ads as a status update.

These are temporary posts similar to “Stories” on Instagram.

Businesses will also be able to grant users access to exclusive updates in exchange for a monthly subscription fee. Meta is expected to take a 10pc commission from those fees.

The features will be housed in WhatsApp’s updates tab.

Overall, WhatsApp has around 3bn monthly users, including 200m businesses.

WhatsApp said the adverts would not appear in personal chats, which use end-to-end encryption, meaning the company cannot see them.

Instead, WhatsApp will use information such as location and language, as well as which channels a user follows, to promote relevant ads.

But users who have linked their WhatsApp account to other Meta-owned apps, such as Facebook and Instagram, will see more personalised ads.

WhatsApp, which accounts for a relatively small part of the group’s business, has long been seen as a potential source of growth for Mark Zuckerberg’s company.

The app is free to download for consumers and only makes money from business users.

Meta reported revenues of more than $42bn in the first quarter, outstripping Wall Street expectations.

Mr Zuckerberg said the tech industry was gearing up for a “pivotal” year, pointing to his company’s progress in AI.