Three is trialing a replacement fixed-line broadband service in Northern Ireland that uses Wi-Fi running off its mobile network.
The operator said the new service is targeted at people such as students and renters.
A router connects to Three’s 3G network, which it said offered average speeds of 9.9Mbps, and its very limited 4G network.
There are two packages on offer, one at £17 per month for 20GB or £20 for 40GB, on either a 30-day rolling contract or a 12-month contract.
Three said the trial was on offer to 500 households as it bids to test consumer interest and the effect of the data allowance on its network.
In mirrors a similar service delivered by UK Broadband-owned Relish in London.
Three Chief Marketing Officer Tom Malleschitz said: “Our home broadband service offers an alternative to a costly fixed-line service which many consumers have no need for.
“Best of all, its super-simple – consumers can just plug and play with no need for complex installation.”
The company made the announcement as it continues its attempts to acquire rival operator O2 UK from Telefónica.
In an interview with the Financial Times at the weekend, Three UK CEO David Dyson promised to work with rivals to maintain two competing mobile networks in the UK.
Earlier this month, Three UK Chairman Canning Fok unveiled a series of measures designed to appease regulators worried that the takeover would reduce competition.