Asda is set to slash its flat-rate calls from 16p to 8p from September 1, and will lower the price of text messages from 5p to 4p.
The move follows a recent announcement by furniture store Ikea that offers its loyalty card members a mobile phone package with calls costing 9p a minute.
Lowest PAYG tariff in UK
Which? technology editor Matthew Bath said:’Asda now offers the lowest pay-as-you-go (PAYG) tariff in the UK, and uses Vodafone’s network to deliver its service.’
Asda Mobile offers low start-up costs, Which? mobile phone experts have found.
Customers who already own a handset can buy a Sim card from Asda for £2.48, including £1 of calling credit.
The supermarket also offers a range of mobile phones from £20. Existing Asda customers will be switched over to the new plan automatically.
Best for occasional mobile users
Matthew Bath added: ‘Asda Mobile’s flat rate certainly is appealing. But while it’s a clear pricing scheme, it might not be for everyone.
‘Flat-rate tariffs are best for occasional users who make short calls to other networks at peak times – and Which? research shows that you’d be better off switching to Asda’s PAYG tariff if you are on a Vodafone Anytime, Orange Racoon or T-Mobile Everyone tariff.’