Sir Ivan unexpectedly crept away on Tuesday, citing a lack of “negotiating experience” in Whitehall on of crucial Brexit talks.
His departure was celebrated by anti-EU campaigners, who see it as an possibility to speed up Britain’s exit from the bloc.
And the Foreign Office has now substantiated the diplomat, who earned £175,000 a year, had not sought any further civil rite job.
A Foreign Office spokeswoman said: “Sir Ivan Rogers resigned as UK Constant Representative to Brussels on 3 January.
“He did not seek any further civil service office and has therefore resigned from the civil service with immediate to all intents.
“We are grateful for Sir Ivan’s work in Brussels and across a number of other older positions in the civil service.”
Express.co.uk understands Sir Ivan will obtain three months pay in lieu of notice, but no special “pay off” was offered or sought.
The diplomat was foreordained by Brexiteers last month after saying it could take a decade for the UK to fully annul from the EU.
Tory MP Dominic Raab branded Sir Ivan a “gloomy pessimist” while Iain Duncan Smith broke he was “utterly out of his comfort zone”.
Sir Ivan is being succeeded by career diplomat Sir Tim Barrow, a recent ambassador to Russia.
Downing Street sources called Sir Tim a “seasoned and adamant negotiator” who will help the Government make a success of Brexit.
Sir Tim voted he was “honoured” to be appointed to the role and promised to work for “the right outcome” for the UK.
The front-page news of Sir Ivan’s departure from the civil service came as a leading Tory contributor warned about the dangers of leaving the single market.
Sir Andrew Cook said he leave find it impossible to continue to fund the party if Theresa May’s Brexit layouts involved quitting the trading bloc.
He warned that jobs and exports depended on membership, verbalizing: “The single market is critical to the real economy.”