The new branch will be operated by Post Office retail partner Sri Nidhi Associates Ltd, who already run the Cow Wynd branch.
The Howgate is around 370 metres from Falkirk’s Garrison Place branch and 260 metres from the Cow Wynd outlet.
The plan is to open the new branch in a vacant unit in the Howgate, offering the same services as the two existing branches.
The Post Office said last year it wanted to franchise its Falkirk branch “to ensure future sustainability”.
Network and Sales Director Roger Gale said: “We are making sure we take the right action to sustain services for years to come”.