It said: "While any loss of customers is disappointing, this represents the smallest decline in SSE's customer numbers since 2013, due to the impact of efforts to improve retention and attract more new customers to SSE".
The board recommended a final dividend of 63.9 pence a share, making a total payout for the year of 91.3 pence a share, up from 89.4 pence a share.
The U.K. will probably introduce a relative price cap that stops companies from offering low fixed tariffs and high standard tariffs simultaneously, he said.
Adjusted pre-tax profit - stripping out one-off items - rose by 2.1% to £1.55bn, boosted by its wholesale electricity generation and gas production business.
Energy giants on Wednesday risked renewed accusations of profiteering as SSE posted a huge rise in its household profit margins. But SSE has warned that it could affect competition in the energy market.
The firm said it is working to keep its dividend cover within an expected range of 1.2-1.4 times, though it is likely to be at the bottom of that range, which means adjusted earnings per share is likely to be lower than it was in 2016/17.
"Over the last few years, SSE has in effect been investing at record levels in order to stand still from a profit perspective", the analysts said in a research note.
Its wholesale business reported an operating profit of 498.2 million pounds after a loss of 481.3 million in 2015/16.
SSE hikes full year dividend..
SSE raised its electricity prices in April by 14.9 per cent for 2.8 million customers.
Exceptional impairments were booked against the Retail unit in the year, particularly the against the technology developments projects relating to an Energy Supply customer billing system which is no longer being progressed.
Adjusted earnings per share rose 5.2 percent to 125.7 pence.
Regarding the proposed cap, SSE said it "would caution against potential unintended consequences of any proposed intervention in what is a rapidly changing and increasingly competitive market".
"We have been clear for some time that 2017/18 presents challenges, and the need to engage constructively with a new United Kingdom government as it takes forward energy policy will be a key priority for the year ahead and beyond", he said. "It supports a stable United Kingdom carbon price, a continued commitment to cost-effective renewable energy, an evolving role for electricity distribution networks and the retention of competition at the heart of retail energy supply", said SSE.