More than 100 million calls by the public to government departments were charged at a premium rate, costing people an estimated £56m, MPs said.
The Commons Public Accounts Committee found a third of Whitehall numbers used by the public last year were higher-rate, including those for victim support, benefit and tax enquiries.
Labour MP Margaret Hodge said their continued use was “not acceptable”.
The government acknowledged a “more consistent” approach was needed.
According to the cross-party committee, which has been looking into the issue, of the 208 million calls made to government departments in 2012/13, about 63% were made to higher-rate numbers.