The Geographic Board's public consultation will last three months from May 28.
After an initial rejection by Wanganui District Council of a name change, the council finally proposed changing the name of the district to Whanganui by a vote of 10-3 in December.
It then conducted its own consultation and received close to 2000 submissions.
Ms Main said the Geographic Board consultation was "an opportunity for our community, as well as people throughout New Zealand, to have their say.
"Submissions made to the council last year were provided to the Geographic Board as part of the council's request to change the name to Whanganui district. People who participated in the council process can make submissions to the Geographic Board as well."
The Geographic Board has said it is interested in reasons provided with submissions, not necessarily submission numbers; the process is not a vote. Following consultation, submissions will be analysed and considered when the board meets on September 23.
Ms Main said the outcome would "provide certainty" to iwi and Wanganui residents. The council proposal followed a request from the Tupoho Working Party to consider changing the spelling.