Legislation has been passed enabling Whanganui and Wanganui to be used as alternative official geographic names.
Debate has raged about the issue, and in 2009 the city's then-mayor Michael Laws labelled the Geographic Board's suggestion for there to be an 'h' in Wanganui as "racist".
It was left to Land Information Minister Maurice Williamson to make a final decision - and he has now endorsed the use of both names.
On Thursday, the Statutes Amendment Bill was passed in Parliament and Mr Williamson told the House it is a special time in his political life.
The minister said people who don't want to use an 'h' don't have to, and those who want to use the 'h' formally can do so whenever they like.
Mr Williamson said he has asked government agencies to change stationery and maps to reflect the change - but has given them a clear directive to make amendments over time, not overnight.
Land Information New Zealand will make the changes to maps - which in future will say Whanganui or Wanganui.