Of course Telstra wants a single Australia-NZ telecommunications environment. The infrastructure here is already deployed, they can come and lobby for LLU and then start providing services without spending anything in infrastructure.

The telco has told a parliamentary inquiry into the Australia and New Zealand Closer Economic Relations (CER) trade agreement there were many benefits in a single market.

Telstra regulatory affairs manager Dr Tony Warren said Australian and New Zealand travellers could save more than $30 million a year in international mobile roaming charges.

Mobile charges could fall from an international roaming rate of up to $2.80 per minute to domestic rates - which vary from 36 cents a minute to $1 a minute depending on the plan.

"You could call Coogee or Bondi by mobile like they were suburbs of Auckland," Dr Warren said in a statement.

Other benefits included savings on the rollout of new technology and networks, a single contract and bill for trans-Tasman businesses, cuts in red tape and a trans-Tasman mobile market with operators offering subscribers seamless service on both sides of the Tasman.