Two women aged, 18 and 19 from Grangetown, and a third aged 19, from London, have been charged with fraud by false representation.
The arrests were made after people were approached by cold callers who claimed to be collecting money for Unicef.
But the charity confirmed no one had been authorised to fundraise in the area.
The women appear at Cardiff Magistrates Court on Friday 1 May. Two other men who were also arrested have been released on bail pending further investigations.
Three people have been charged over allegations of fraudulent fundraising in Cardiff.