The ContactPoint database will not go live until full security checks have been carried out to make sure that the information it contains is protected.
"Over the past few months we have been considering the substantial stakeholder feedback we have received, and looked at the implications that the proposed changes could have on the system," said Children's Minister Kevin Brennan in a statement.
"It is clear from the considerable work we have done so far that we will need more time than originally planned to address the changes to ContactPoint which potential system users suggested."
The database was set up after the death of Victoria Climbie to better coordinate the protection of children by sharing information between government agencies.
It would contain details on every child in Britain, but has been sharply criticised by many.
Shadow Children's Minister Maria Miller said: "The government should also use this opportunity to see whether it is really necessary to have a database of every single child in the country, accessible to 330,000 people, given the concern that this could overload the system and lead to a 'dumbing down' of information.
"We have always supported, as an alternative, a slimmed-down tightly controlled database which focuses on genuinely vulnerable children."
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