Ms Berry said the changes were as a result of the changing way customers were using post services and part of a wider plan to future-proof the store network.
"Globally, people are sending fewer letters now and doing more business online. However, people are sending more parcels."
Customers would still be able to pay bills, register cars and access all postal and courier services at the new site but would need to visit the Whangarei Town PostShop or use phone or internet banking for more complex banking services.
The Onerahi box lobby would be relocated to the pharmacy's premises and there would be no change to customer PO box numbers.
Ms Berry said it was unclear, at this point, whether NZ Post staff from the Onerahi's team of five would be employed with the new franchisee.
Unichem Onerahi Pharmacy owner Frances Hill, who has worked in Onerahi for nearly 10 years, believed customers would respond positively to the change in the community.
"It's a great location for locals running errands and will be a great fit for New Zealand Post's services.
In June last year, NZ Post announced it would also close down its Paihia and Kawakawa branches and find community franchisees to provide services on its behalf.
There are PostShops combining Kiwibank and post services at Dargaville, Mangonui, Kaikohe, Kawakawa, Kerikeri, Kaitaia, Paihia Central, Whangarei Central, Tikipunga, Kamo, Kensington, Te Mai West and Otaika, with many of the postal and banking services running under agencies or franchise operations, usually within other businesses such as grocery stores or bookshops.
Government and community relations manager Holden Hohaia was also in Northland in the last fortnight meeting community groups and businesses.
Ms Berry said NZ Post was still in talks with businesses in Paihia and Kawakawa, with a view to finding outlets that sat well with the "community ethos" of the postal company.
"Post business drives a high foot traffic into a business so it's a great opportunity for additional revenue."
She said, however, that space requirements proved the biggest challenge for many interested parties.