Prosecutors said in a statement today that 23-year-old Isabella Sorley and 25-year-old John Nimmo, both from northern England, would be charged with "improper use of a communications network" over messages to Caroline Criado-Perez.
Two other suspects will not be charged, while the statement said a fifth was still being investigated.
Criado-Perez was one of several women who went public earlier this year to complain about sexually explicit abuse received on Twitter from online bullies and provocateurs, often nicknamed "trolls." Twitter responded in August by making it easier to report abuse.