The figures were released today in the interim report for the six months ended 31 December 2017.
The company said it reached the one million active client mark in November 2017 and this has since risen to 1,015,000.
Client retention rate has “remained very high at 94.5%”, the report stated.
The firm reported that its helpdesk has been regularly handling call levels more than 18% higher than last year, and client instructions averaged one million a month.
The report said: “These are all record levels.”
Key points from the publication included:
· Net new business of £3.34 billion
· Assets under administration up 9% since 30 June 2017 to £86.1 billion.
· Profit before tax increase of 12% to £146.9 million.
· Interim dividend up 17% to 10.1 pence per share (H1 2017: 8.6p).
Chris Hill, chief executive officer, said: "I'm pleased to report another strong period of growth for Hargreaves Lansdown for client numbers, revenue and profit.
“We have a significant market opportunity with a clear strategy focused on our clients' needs and offering great value and service to them.
“Our aim of making it easy and efficient for clients to manage their savings and investments in a secure environment and empowering them to save and invest with confidence is at the heart of our business, and was reflected in our continued growth during the first half of our 2018 financial year."