Moon joined the firm as business development director and Cayzer as business development assistant on Monday, 25 September.
They join CEO Penny Lovell, also a former Close Brothers employee, who is responsible for leading Sanlam’s offering for high net worth clients.
Lovell said: “Both Jonathan and Will are highly talented professionals with a deep understanding of the needs and requirements of high net worth individuals.
“I have worked with them closely over a number of years and I am confident that, together, we can create a first-class high net worth Private Office proposition at Sanlam UK.”
Moon was previously business development director at Close Brothers, and also held roles at Tilney Group while Cayzer spent two years at Close Brothers after a stint working with Fleming Family and Partners.
Sanlam has embarked on a vertical integration since the group CEO Jonathan Polin joined the wealth manager in 2015.
It now controls more than £12bn in client assets.
Polin said: “The launch of a Private Office extends our service in the UK and bolsters our ability to offer tailored solutions for high net worth clients.
“Penny’s team will deliver a high quality Private Office proposition and will be central to us cementing our position as one of the UK’s leading wealth managers.”