England's newest city has received the formal legal document which entitles it to change its status.
Borough councillors at Chelmsford in Essex were presented with a red box containing Letters Patent authorising the town to call itself a city.
The status was awarded earlier this year as part of the Queen's Diamond Jubilee celebration.
Roy Whitehead, Conservative council leader, said the new city would also have a new emblem.
He said the box containing the Letters Patent was collected from House of Lords last week and inside is a message from the Queen and a large seal.
Mr Whitehead said: "We officially open the box at 18:00 BST in the council chamber. The Mayor will enter... we will say a few words and unveil this officially to the public. From that moment we are officially a city."
He said the document would eventually be put on public display.
"We have plans to rebuild the council chamber and we will then put up a proper display of this so all residents can see it... because it is a splendid document," he said.
A new logo for Chelmsford will also be unveiled but Mr Whitehead said care was being taken not to waste money.
"We have plans to unveil signs but residents are keen we don't spend a great deal of money changing all the signs - we don't want to repaint all the dustbins," he said.
"We have to be very cautious in that fine line of celebrating and not wasting money."