Aldi is introducing 99p greeting cards supplied by Card Factory across its entire 840-store UK estate.
The discounter has previously offered cards for special occasions including Christmas but this will be the first time they will be available year round.
They will include birthday, anniversary, congratulations and thank you cards.
The move follows a trial in Aldi stores in Yorkshire and the south-east launched earlier this year. The wider rollout will be completed by the end of October.
Aldi has also announced that all cards, as well as festive wrapping, will be free of non-biodegradable glitter by the end of 2019 as part of its work to cut microplastics.
“The convenience of buying a quick birthday or anniversary card along with your groceries has meant greetings cards are increasingly the kind of product shoppers now expect to buy as part of their weekly shop,” said Aldi buying MD Julie Ashfield.
“We carried out trials in two regions earlier this year and the feedback was overwhelming - our customers loved being able to buy a range of quality cards at a simple, low price point.”