Nowhere was the swap more difficult than in the rebel-held north of Ivory Coast, once the regional economic powerhouse, where banks have been shut since civil war erupted in September 2002.
Long queues snaked through the United Nations peacekeepers' base in the rebel stronghold of Bouake on Friday, where central bank officials had set up makeshift counters to exchange the banknotes.
Staff here had the added task of checking the banknotes' serial numbers to filter out those stolen from central bank branches in the rebel zone. Tired after arriving at 5 am and sitting rather than standing in the queue was Fatou Traore, 35, who runs a vegetable stall in Sakassou, about 40 km (25 miles) south-west of Bouake.
"It's going well but it's a bit slow," she said, clutching her earnings in a black plastic bag.
"If they could take 50 people at a time, it would be over much more quickly," she said, referring to a minibus shuttling groups of 10 into the UN base to fetch their new notes.
Those who could afford it saved on waiting time by buying a spot further up the queue from empty-handed people standing in line long enough to make their place marketable at about 2,000 CFA francs ($4).