Sainsbury's is removing advice to freeze food "on day of purchase" from its labels and informing customers it can be done up until the use-by date.
The UK's third-largest supermarket chain believes 800,000 tonnes of food a year could be saved from the bin.
The move, in conjunction with the Waste & Resources Action Programme (Wrap), was welcomed by the government as "good news for hard-pressed family budgets".
The average UK family wastes up to £50 worth of perfectly good food a month.
The supermarket will advise freezing food as soon as possible, any time up until the use-by date.
"There is no food safety reason why it cannot be frozen at any point prior to the use-by date," said Beth Hart, head of product technology for fresh and frozen.
"As one customer pointed out to me while discussing the previous labelling, 'How does the product know which day I purchased it on?"'
Research by Wrap has found that 60% of people believe food has to be frozen on the day it is bought - a view reinforced by current labelling.
"Now we can all look in our fridges and know that we can freeze most items which are about to go out of date and enjoy them at a later time," said Andrew Parry, Wrap consumer food waste prevention manager.
Environment Minister Lord Taylor said: "This is good common sense by Sainsbury's and it's good news for hard-pressed family budgets."