The firm also reported that its operating profits were £1.15bn last year – an increase of 7%.
Profit before tax went up by 10% in 2013 to £1.134bn and profit after tax went up by 12% to £896m.
The company's net cash generation increase includes a 16% rise last year.
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Nigel Wilson, group chief executive, said:
"Disciplined investment in growth, effective management and rigorous cost control has enabled us to more than triple net cash since the financial crisis.
"Legal & General moved up another gear in 2013, delivering record financial results and accelerating growth across all areas."
Annuity premiums grew by 78% to over £4bn and protection gross premiums were over £1.3bn.
Mr Wilson said: "We have delivered significant outperformance during lean economic times and are building momentum as the economy recovers. We now have over 10 million customers."
However, he warned there are still risks to the economy, the largest being "the persistent backdrop of political and regulatory uncertainty".
Mr Wilson said this could "undermine the confidence of businesses to invest for long-term growth in the UK."