The Swedish Central Bank is removing the older notes as it adds redesigned bills with updated security features to the pot.
People have until June 30 to spend the bills though it will be possible to deposit them in a Swedish bank account until August 31. As a last resort, starting in September, the old bills can be sent in to the central bank, known as the Riksbank in Swedish, where they can be redeemed at a cost of SEK 100 per deposit.
"If people have these old notes, they have to use them before June 30 because after that they will become invalid," Susanna Grufman, head of the bank notes and coin division at the Riksbank, tells Radio Sweden.
In late May, the central bank calculated that 57 million of the old banknotes worth SEK 2.6 billion were still in circulation.
The old bank notes feature author Selma Lagerlöf on the 20-krona note, opera singer Jenny Lind of the 50-krona note and former king Gustav Vasa on the 1,000-krona note.