Donor information website Intelligent Giving will restart its work in the next few weeks and be fully relaunched in the spring.
Staff from NPC will start blogging about the new site over the next few weeks and will publish a new methodology report, outlining Intelligent Giving's revised approach, within the next six weeks.
Tris Lumley, head of strategy at NPC, said the new version of Intelligent Giving would take a similar approach to evaluating charities as it had previously done and would retain its "conversational" tone as well as its charity profiles, blogs and forums.
But he said it would place a greater emphasis on the extent to which charities kept their supporters and the general public informed about their effectiveness and whether they were reaching their targets.
"We'll be more interested in what charities tell people about their plans and how easy it is for the public to find out how they operate," he said.
He said NPC was still trying to raise funds for Intelligent Giving's work, but because it was not a front-line charity it struggled to attract donations.
A statement on the Intelligent Giving website said the organisation would contact the charities about which it had written reports, to tell them "what will be happening to their profiles".
The new site is expected to be launched in April.