The company building the national broadband network has posted a loss of nearly $1 billion for last financial year.

The NBN Co's annual report has just been released, and shows its total loss has grown to $903 million.

The company, which is chaired by former Telstra boss Ziggy Switkowski, made revenue of nearly $66 million.

A quarter of that was telecommunications revenue, but most was from interest on the company's cash balances.

The annual loss is significantly lower than the projected $1.3 billion loss forecasted in the NBN's corporate plan.

The broadband network is currently in the build phase, which the company has said would impact profits.

Earlier this month, Communications Minister Malcolm Turnbull set a deadline for a strategic review of the broadband project.

He said the review will focus on providing "plain, unvarnished facts" about how much the project will cost and how long it will take to complete.

"We do not want spin, or for the company to tell us what they think what we might like to hear," he said on October 3.

"Labor has made shocking mistakes. There are billions of dollars that Labor has wasted that we will never be able to recover. This has been a shockingly misconceived, wasteful exercise in public policy.

"So we need to know, 'what is the state of the project right now accurately?'

"We then need to know what the real trajectory of it would be were the previous policy settings to be kept in place."

Mr Turnbull, who was speaking on October 3, said the review would be completed within 60 days.