The firm also said that following its second client asset migration at the end of November, 80% of UK investment platform assets have now been migrated onto the new platform technology.
The final migration of assets to the new platform is scheduled to complete over the weekend of 27 February.
Paul Feeney, CEO of Quilter, said the new UK platform will be “transformational” for the firm and will drive future business growth.
According to its latest quarterly trading statement, growth in AUMA for the firm was supported by improved net flows and positive market movement.
Fourth quarter gross sales dropped to £2.8bn (Q4 2019: £3.5bn) with net inflows holding steady at £0.4bn (Q4 2019: £0.5bn).
Total gross sales for 2020 were £10.9bn (2019: £12.3bn) which was partially offset by strong net inflows of £1.6bn (2019: £0.3bn).
For the Quilter Investment Platform, modestly lower gross sales of £5.7bn in 2020 (£2019: £6bn) were offset by improved retention with higher net inflows of £1.5bn (2019: £0.9bn).
Integrated net inflows in Quilter Investors, Quilter Cheviot and Quilter International ended a volatile year at £2.3bn.
Mr Feeney said: “2020 was a year of unprecedented challenges in so many respects and one of extraordinary market volatility.
“I am particularly pleased by the consistent performance of our UK platform throughout the year and with it delivering a good final quarter despite the major migration completing at the end of November.”