People will be able to refill water bottles for free at tens of thousands of shops, cafes, businesses and water fountains across England under plans by the water industry.
The scheme aims to prevent the use of tens of millions of disposable plastic water bottles a year, as part of efforts to curb the "harmful tide of plastic waste" on land and in the seas.
Members of the public will be able to use an app on their phone to find the nearest refill point or look out for a special sign in shop windows as the nationwide scheme is rolled out.
The plans will see a network of high street retailers, coffee shops, businesses and local authorities offering free refill stations in every major city and town in England by 2021, industry body Water UK said.
Whitbread is the first company to sign up to the national scheme and has pledged to provide free drinking water for customers and passers-by in each of its 3,000 Costa Coffee and Premier Inn locations from March.
The national programme, which comes amid heightened public concern over plastic pollution in the world's oceans and political pledges to tackle plastic waste, draws on the success of the Refill campaign.
The campaign has more than 1,600 refill stations across the UK, with some water companies taking part in local schemes: Anglian Water in Norwich, Northumbrian Water in Durham, South West Water in Cornwall and Bristol Water in Bristol.
In Bristol, where the scheme launched in September 2015, there are more than 200 refill points across the city centre.
Refill Bristol estimates that if every city resident refilled a bottle once a week instead of buying a single-use plastic bottle, the city could cut the use of throwaway bottles by 22.3 million a year.
The Refill scheme, already taking place in 13 towns and cities in England, encourages cafes, bars, banks, galleries, museums and other businesses to sign up to a free app and put a sticker in their window to alert passers-by they are welcome to fill up their bottle for free.
Under the plans for a nationwide scheme, water companies will work with Refill to develop local action plans with partners, with the network and national app in place by 2021.
Some water companies are also looking at installing new public drinking fountains and restoring some historical ones which have fallen into disuse.
Natalie Fee, founder of City to Sea, the organisation behind the Refill scheme, said: "We've seen a huge appetite for our Refill campaign across England, from individuals wanting to make a difference in their community to national chains keen to offer free refills to their customers.
"Our Refill app puts the power to stop plastic pollution in people's hands - and now thanks to the water industry we'll be able to help everyone, from local communities to airports, to provide free refills on the go."
James Pitcher, director of sustainability at Whitbread, said: "With over 3,000 Costa stores, Premier Inn hotels and restaurants the length and breadth of the country we can make it easier for people to refill for free, helping to reduce the number of plastic bottles being littered or thrown away."
The announcement comes after London mayor Sadiq Khan unveiled plans for 20 new water fountains in the capital and support for "refill" pilots for businesses such as shops and cafes to offer customers free tap water.