Two former News of the World journalists have been charged with conspiring to hack phones, the Crown Prosecution Service has said.
The defunct newspaper's ex-deputy editor Neil Wallis and ex-features editor Jules Stenson are accused of conspiring to listen to voicemails between January 2003 and January 2007.
The charges are part of Operation Pinetree into ex-NoW features staff.
Both will appear before Westminster Magistrates' Court on 21 August.
Gregor McGill, from the Crown Prosecution Service (CPS), said it had been decided there was "sufficient evidence for a realistic prospect of conviction and that a prosecution is in the public interest".
He said the CPS had authorised the Metropolitan Police - which is leading the operation - to charge the pair.
Six other journalists who were held as part of the inquiry have already been told they will face no further action.
Separately, the BBC has learned officers from Operation Pinetree have now warned about 1,300 people they may have been victims of phone hacking.
BBC home affairs correspondent Tom Symonds said police believed there could be as many as 1,600 victims.
He said many were likely to be celebrities and people already known to have been targeted by the NoW news desk.
However, our correspondent said the number could also include hundreds of people identified for the first time.
The list of victims has been drawn up based on data from a PalmPilot digital device seized by police from Dan Evans, a former NoW and Sunday Mirror reporter.
Several sources have told the BBC the PalmPilot contained up to 800 names, while a separate list of names given to Evans by a senior NoW journalist contained a further 800 names.
The BBC understands around half of the 800 names on a contact list on the PalmPilot could have had their phones hacked while Evans was at the Sunday Mirror.
Our correspondent said the revelation was the "first time a figure has been disclosed estimating the number of potential victims of hacking by Mirror titles".
Evans was last month given a 10-month suspended prison sentence after he pleaded guilty to two counts of phone hacking as well as making illegal payments to officials and perverting the course of justice.
He had admitted one count of hacking at the Sunday Mirror, where he worked from 2003-2005 and one charge from his time at the NoW, where he worked from 2004-2010.
News International - now called News UK - which owned the NoW has admitted liability for phone hacking.
Trinity Mirror, which owns the Sunday Mirror, has insisted its journalists worked within the law and within the Press Complaints Commission's code of conduct.
The company has set aside £4m to cover the cost of resolving claims from hacking victims - but admitted in its 2014 interim results the true cost could be higher as further victims came forward.
Trinity Mirror declined to comment to the BBC on Wednesday but has previously denied hacking took place at its titles.
Mirror Group Newspapers is being investigated by police under Operation Golding.