Regulator, Ofgem, has given the go-ahead for the investment, but the figure is £105 million less than proposed by SSE.
The transmission link is designed to bring wind energy from the north of Scotland to highly populated areas further south. The link is expected to come online in 2018.
Back in July, Ofgem granted construction consent for the project, but retained the power to approve the level of funding in order to ensure bill payers get the best possible deal, it said at the time.
Earlier in December, SSE handed ABB the £460 million (EUR 580 million) contract to supply the cable system for the project.
The company will design, engineer and install the 160-kilometres of cabling between a substation in Keith, Moray and another converter at Spittal in Caithness.
Scotland in aiming to generate 100% of its power from renewables by 2020 and already exports energy to the rest of the UK.