The tax has been put in place to help curb obesity levels, as one in three children leaves primary school overweight. The Treasury says recipe alterations have already cut out 45 million kilograms of sugar per year.
Brits will be paying higher prices for some soft drinks after the country's sugar tax on the sweet beverages came into effect on Friday.
Announced in March 2016, the tax has already seen more than 50 percent of manufacturers modify their products to ensure they are below the levy's sugar limit, Britain's Treasury said.
"Our teenagers consume nearly a bathtub of sugary drinks each year on average, fueling a worrying obesity trend in this country," Public Health Minister Steve Brine said.
"The soft drinks industry levy is a ground-breaking policy that will help to reduce sugar intake, whilst funding sports programs and nutritious breakfast clubs for children," Brine added.
Companies will pay 24 pence (27 euro cents, 33 US cents) per litre of drink if it contains 8 grams of sugar per 100 millilitres and 18 pence per litre of drink if it contains between 5–8 grams of sugar per 100 millilitres.
Because of manufacturers' efforts to reformulate their product, the Treasury now expects the levy to raise only about £240 million (€275.5 million, $338 million) in its first year, less than half the previous estimate of £520 million.
Soft drink producers such as Coca-Cola, Britvic and Lucozade Ribena Suntory have amended their recipes, but with more than 10 grams of sugar per 100 millilitres, Coca-Cola Classic — the nation's top-selling branded soft drink — and Pepsi is both subject to the tax.
Retailers Tesco, Asda and Morrisons have also modified their own-brand soft drinks to be below the levy's threshold.