Mr Spooner said a key to retaining the expertise and knowledge means Murray Carey and Douglas Wilson will be retained as consultants under the new banner.
He said while there was a lot of history in those original names, the new brand created a new pathway.
"Douglas and Murray are with us for at least another five years so from a client perspective everyone will be dealing with the same staff."
All staff across both firms have been retained in the amalgamation, 17 in all, 10 from Sewell & Wilson and seven from Carey Hood & Co.
"The thing is this brings together a wealth of knowledge, giving us more expertise and certainly more experience," Mr Spooner said.
Spooner, Hood and Redpath will cover everything in terms of accounting. They have a lot of commercial and farming clients while auditing remains another major string to their bow.
Mr Hood said creating the new practice could be regarded as succession planning. "Murray and Douglas will start to wind down at some stage but they're still very active in the business and we don't see that changing in the near future. The key from our perspective is them being able to help transition clients as the merger goes through."
The three directors said the relationships with clients were paramount. Their client base stretches throughout New Zealand.
"Technology means we're able to operate well beyond Whanganui," Mr Spooner said.
He said the firm would always be looking for new business and there was potential for growth with the extra resources.
Mr Spooner said the "big thing" from their point of view was remembering where they had come from.
"It is important we remember the Carey Hood and Co and Sewell & Wilson legacy. They've given us a really strong foundation. "The expertise remains in place. It's just the name plate that's changed," Mr Spooner said.