An extra £20m has been saved by Nottinghamshire County Council on top of planned cuts, it has been announced.
The authority is looking to save £150m in the next three years, due in part to a drop in central government funding.
Coming on top of £29m in budgeted savings, the extra money in 2010/2011 included underspends on adult social care and children's services.
But the union Unison said the figures showed the Conservative-led authority was cutting harder than necessary.
The underspend on adult social care totalled £9.5m, while children and young peoples services used £3m less than expected.
Other savings included £2.9m from finance and property and £2.21m from transport and highways.
Council officials said restricting non-essential spending, like staff travel and conferences, had also saved more than £1m.
They added that most of the money would go towards redundancy payments. About 2,500 posts from a non-teaching workforce of 11,000 are due to be lost.
The council itself admits the eight most senior posts it needs to lose will alone cost £1m in redundancy.
Reg Adair, the county council's cabinet member for finance and property, said: "This saving is not about reducing front-line services which would affect Nottinghamshire residents.
"We are determined to drive out every saving and make the council a more cost effective and value for money organisation."
Unison said the size of the underspends were a cause for concern, not celebration and showed deeper than needed cuts which were bound to damage services.