Tinder is charging people over 30 up to 48 per cent more for its premium service, an investigation has revealed.
Which? said its findings suggest possible discrimination and a potential breach of UK law by the popular dating app.
The consumer group also initially accused Tinder of hiking prices for young gay and lesbian users aged 18-29, but has since backtracked on this.
A statement from Which? said: 'Having initially chosen not to provide further information, Tinder has since revealed that it offers discounts to users aged 28 and under in the UK.'
It added that the dating app 'claimed that by including 29-year-olds in our analysis of the relationship between price with age and sexual orientation, "the results would be skewed to make it appear that LGBTQAI+ members paid more based upon orientation, when in fact, it was based upon age".'
Which? said that in light of the new information, it has 'no evidence that sexual orientation impacts pricing for young Tinder users'.
Tinder had previously said it was 'categorically untrue' that its pricing structure discriminates by sexual preference.
The dating app claimed that this price difference was 'a discount for younger users', but Which? found that this is not made clear to people using the app.
Which? has reported its findings to the Equality and Human Rights Commission (EHRC) and the Information Commissioner's Office (ICO) and called on them to investigate whether there has been a breach of UK law.
The EHRC, Britain's equality regulator, said it was looking into the issue and called the findings 'concerning'.
Tinder is charging people over 30 up to 48 per cent more for its premium service, an investigation has revealed
Those in the 30-49 age bracket paid 48 per cent more (£24 difference) and over 50s paid 46 per cent more (£23.19 difference) on average, for a 12-month Tinder Plus subscription
The consumer group asked almost 200 mystery shoppers to create real profiles and make a note of prices quoted for Tinder Plus, a premium package with perks such as unlimited 'Likes' and 'Rewinds' and the ability to undo accidental selections.
Those in the 30-49 age bracket paid 48 per cent more (£24 difference) and over 50s paid 46 per cent more (£23.19 difference) on average, for a 12-month Tinder Plus subscription.
Which? found that the full extent of how personalised pricing is applied is not clear on Tinder's app — with no explanation to customers that their personal data could be exploited in this way.
It is occasionally justifiable under UK law to offer age-based price variations for the same product or service, such as discounts to over-65s or students, where it can be shown there is a legitimate basis for this.
However in this specific example, it was not clear why over-30s were paying more, Which? said.
The investigation suggests that Tinder has an algorithm that is opaque and unpredictable.
Across the entire mystery shopping exercise, quotes for a year's access to Tinder Plus ranged wildly from £26.09 to £116.99, with 20 different prices quoted in total.
Which? analysed Tinder's terms of use and privacy policy and found that users were not made aware of such vastly different pricing.
