The ASA is investigating Three's latest ad campaign after receiving five complaints about its claim to be the only "real" 5G network, including one from rival EE.
The ad watchdog confirmed it would investigate whether the ad, which features on social media and has appeared in print, breached its rules. The spot states: "If it's not Three, it's not real #5G."
A Three UK spokeswoman defended its claim. In a statement, she said the advertising is designed to inform customers it will offer "the fastest 5G network, based on Three having three times as much 5G spectrum as any other operator".
"We are also the only operator to have 100 MHz of contiguous spectrum. ITU considers this the gold standard for 5G, enabling consumers to take full advantage of what 5G has to offer."
5G, which is fifth generation mobile internet, promises faster download, upload and streaming times. It has been hailed for paving the way for the 'internet of things' – presenting an opportunity for brands.
Since May it has been launched across a number of cities in the UK by operators including Three, EE and Vodafone. O2 and BT are set to launch 5G in the coming months.
An EE spokesman said: "Three’s claim is false, and deliberately aimed at misleading consumers. Our customers have been using real 5G since we launched the UK’s first 5G network, back in May."
Writing in Campaign on Monday, Katharine Hansford, a mobile specialist in the digital transformation team at Zenith, argued that 5G will transform connectivity and power more creative opportunities for advertisers.