Trott, with cyclists Dani King and Joanna Rowsell, won a gold medal in the Olympic team pursuit contest.
The Royal Mail decided to paint a postbox in Harlow, where Trott was born.
But after Trott tweeted that her hometown is Cheshunt, Herts, the firm said it would paint one there also.
The cyclists are also featured on a new stamp.
'Not my hometown'
Trott initially wrote on Twitter: "when my postbox is painted gold tweet me your pics with it :-) x".
But after discovering the mistake, she added: "So people i need you to tweet @PostOffice for me.. my postbox is going in harlow which isnt in my hometown Cheshunt is where it should be!!"
Tim Cowen, of Royal Mail, said the mistake was made because her home town was listed as Harlow on the Team GB website.
"We tweeted her straight back to say we'll be delighted to do one in Cheshunt as well," he said.
Mr Cowen said the company would paint a box near where she went to primary school, but it could be delayed until Monday due to Britain's run of gold medals.
"We are running a little short on gold paint, which is testament to Team GB's success. We'll be getting more supplies tomorrow," he added.
Royal Mail has pledged to transform one postbox from red to gold in the home town of every British Olympic champion during the Games.
OP: This is where I live and I actually walked past the bloke painting the postbox a different colour this morning and wondered why. Well now I know!