As of next month there'll be only one official way to spell Whanganui, and that's with an "H".

Land Information Minister Louise Upston's announced an "H" is to be put into the official spelling of the district's name, matching the spelling that currently applies only to the town and the river.

It'll apply to all official names and government agencies.

Local MP Chester Borrows says the change is the right move.

"Whanganui without an 'H' can either mean 'many big places' or 'a long wait', and it's supposed to reflect a 'large estuary' or 'river mouth', and that's what Whanganui with an 'H' does."

Labour MP for Te Tai Hauauru Adrian Rurawhe says people in Whanganui will be feeling elated about the decision and how quickly it will take effect.

"It's been a long, arduous battle to get the name corrected, and as the tribunal said last month, there is only one legitimate name, and that is the name that is spelt with an 'H'."

Louise Upston says although Crown agencies will have to use the "H", private businesses won't.

However she expects more and more of them will end up using it over time.

But, Whanganui mayor Annette Main says local businesses don't need to feel obliged to change anything, including their company names in order to fit with the new spelling of the district's name.

"Businesses don't have to change their names. It's your personal choice, it's your business name, and this will just happen gradually," she said.

"There's no need for us to go out immediately and start changing everything."