Brian Walden, the WDHB's strategic and corporate manager, said the project would mean financial services across all health boards would operate on a shared system.
"It's not uncommon among big businesses to have shared systems across different sites," he said.
"However, because every DHB must agree to operate in the same way, we are being cautious. We have to make sure the system works for us."
Mr Walden said his major concern was that the centralisation could result in the loss of up to five full-time equivalent jobs in Wanganui, although that wouldn't happen until 2015.
Some of the policies required only minor changes to the way the WDHB operated, but some would "get to the heart" of how their business was run.
"One example is that HBL is saying that anyone in the organisation can issue a credit note, but we would prefer that to be restricted."
The WDHB's risk and audit committee have asked for clarification on parts of the policies before accepting them.
Mr Walden said the business systems centralisation was only one strand of the project; the next would involve food and laundry services, which the WDHB would consider in mid-2014.