Mainstay

Start a conversation

About

An independent firm, built around partners who do the work.

An independent firm, built around partners who do the work.

An independent firm, built around partners who do the work.

Founded in 2009 by three partners who wanted to work differently: fewer clients, smaller teams, and advice measured in results.

Our story

We started Mainstay because the big firms had become very good at selling projects and very bad at finishing them. Fifteen years on we are still small on purpose, still owned by the people who do the work, and still judged on one thing: did it work.

We started Mainstay because the big firms had become very good at selling projects and very bad at finishing them. Fifteen years on we are still small on purpose, still owned by the people who do the work, and still judged on one thing: did it work.

We started Mainstay because the big firms had become very good at selling projects and very bad at finishing them. Fifteen years on we are still small on purpose, still owned by the people who do the work, and still judged on one thing: did it work.

2009

2009

2009

founded in London

48

48

48

people across three offices

140+

140+

140+

engagements delivered

92%

92%

92%

repeat clients

What we believe

Three rules we do not break

Three rules we do not break

Three rules we do not break

01

01

01

Say the hard thing

We are paid for judgement, not comfort. If the answer is unwelcome, we say it early and show the evidence.

02

02

02

Senior by default

Partners do the work. No pyramid of juniors, no handover after the pitch.

03

03

03

Results or nothing

We measure success in your P&L, a year after we leave, and we put fees at risk to prove it.

Offices

Three cities, one team

Three cities, one team

Three cities, one team

London

14 Harbour Street

London EC3N 4AB

+44 20 7946 0120

New York

220 Fifth Avenue, 9th floor

New York, NY 10001

+1 (555) 010-2200

Singapore

8 Marina View, #32-01

Singapore 018960

+65 6800 1180

Let’s talk about what’s next.

Let’s talk about what’s next.

Let’s talk about what’s next.

One conversation, no pitch. If we can help, we will say how. If we cannot, we will say who can.

Mainstay

An independent strategy and operations consultancy. Senior partners, short timelines, results you can put a number on.

Start a conversation

© 2026 Mainstay Advisory Partners. All rights reserved.

Template demo content. Replace with your own.

Create a free website with Framer, the website builder loved by startups, designers and agencies.