Redundancy costs for a council's chief executive post will be almost £475,000 ahead of a planned merger.
Dorset's nine authorities are due to become two unitary councils in April.
Dorset County Council's chief executive Debbie Ward has announced her departure from the soon-to-be axed post. She has been in charge for six years.
In August, the new Dorset authority said redundancy costs for four chief executives could cost £1m.
The county council has not yet said whether that means projected costs for those job losses are expected to rise.
It said no decisions had yet been made, with costs varying between councils and also depending on age and length of service.
The county council said Ms Ward, who was the first female to be appointed as chief executive, would receive a £129,914 redundancy payment, plus £40,211 "in lieu of 13 weeks' notice" and a pension top-up of about £303,650.
Her annual salary was £155,055.
In a statement, the council said: "It is important to stress that Debbie will not be receiving a severance package of half a million pounds: she will be receiving £130k as redundancy and £40k payment in lieu of 13 weeks' notice.
"The pension strain of just over £300k is what [the council] pays to the pension fund - not to Debbie direct."
The government is proposing a cap on public sector exit payments of no more than £95,000.
Bournemouth, Poole and Christchurch councils are set to merge in April.
Dorset County, East Dorset, North Dorset, Purbeck, Weymouth & Portland and West Dorset councils will form a second council.
Earlier this month, shadow council members of the latter heard an extra £400,000 may be needed to complete its set up.
Supporters of the changes say they could save £108m over six years.
Ms Ward is set to leave Dorset County Council on 30 November.
The authority said Mike Harries, current corporate director for environment and economy, had been recommended by the staffing committee to replace her until 31 March.