Advisory: A Fractional CSO Without the Six-Figure Salary
Your board has hard ESG questions. Your investors are asking due-diligence questions you don't have answers to. Regulations move every month. Greenwashing risk keeps the CEO up at night. But you're not ready to commit £100k+ to a full-time CSO hire.
Our advisory retainer puts a senior sustainability practitioner on call — in your board pack, in your inbox, in your hardest decisions — for a fraction of the cost of an internal hire.
When clients call us for advisory
Six scenarios where a fractional advisor is the right answer, not a full-time hire and not a consultancy project.
"Our board has questions we don't know how to answer." Sustainability NEDs ask hard things. The CFO wants ESG translated into £. You need someone in the room who's seen it before.
"We're worried about greenwashing risk." Marketing wants to put "carbon-neutral" on the homepage. Legal wants the GCD audit. Someone needs to triage what claims are defendable and what's a CMA Green Claims investigation waiting to happen.
"Regulations move faster than we can read." EU Omnibus, CSDDD, ISSB jurisdictions, UK SDS, SBTi v2, EUDR timelines — you want monthly briefings without subscribing to a dozen newsletters. Filtered, contextualised, with what-it-means-for-you commentary.
"Our investors are asking sophisticated ESG questions on every call." PCAF financed emissions, SFDR PAIs, ISSB transition plans — questions where wrong answers cost capital. You need a thinking partner who's seen the questions before.
"We're preparing for exit / IPO and ESG due diligence is intense." Buyers and underwriters now run ESG-DD as a standard workstream. Gaps surface late. An advisor de-risks the timeline 6–12 months out.
"We'll hire a CSO eventually but not yet." An advisor structures the eventual hire — level, scope, mandate, KPIs, comp range — while doing the role at fractional intensity until you're ready.
Advisory tiers
All tiers: senior advisor, named in the engagement letter. Direct lines, no juniors in the middle.
Lite
For early-stage / SME boards needing periodic counsel
per month
- 1 day per month of advisor time
- Quarterly board attendance (remote)
- Monthly regulatory horizon-scan briefing
- Email response within 1 business day
Standard
For mid-market or post-IPO companies needing active counsel
per month
- 2 days per month of advisor time
- Every board meeting attended (in person where useful)
- Investor / lender call support
- External statement review (greenwashing risk)
- Direct CEO line, response same business day
Fractional CSO
For companies running ESG seriously but not ready for a full-time CSO
per month
- 4 days per month of advisor time
- Embedded in exec team operations
- Functions as your interim CSO until you hire
- Designs CSO hire spec when you're ready
- Direct lines to whole exec team
6 or 12-month contracts. 30-day notice. No setup fees. Travel charged at cost.
The economics
Fractional CSO vs full-time hire vs consultancy. Honest comparison.
Full-time CSO hire
Salary + benefits + recruiter fee + 6 months ramp-up.
When it makes sense: ESG is central to your strategy, you have the role definition, and the workload justifies a full-time post.
ESG:ONE fractional
Lite, Standard or Fractional CSO tier. Senior practitioner, no ramp-up, no recruiter fee.
When it makes sense: You need senior counsel but the workload doesn't justify a full-time hire yet. The Fractional CSO tier handles the role until it does.
One-off consultancy
Fixed price, fixed scope, project-based.
When it makes sense: You have a defined task (materiality, baseline, CSRD readiness). Doesn't replace ongoing advisory.
Advisory FAQs
What is fractional ESG advisory?
A senior sustainability practitioner (typically former CSO, Big-4 partner or framework author) on retainer 1–4 days per month. They attend your board, advise your CEO, sense-check your strategy, watch the regulatory horizon, and review high-stakes external statements before they go out.
Who is advisory for?
CEOs and boards of companies who need senior ESG judgement but aren't ready to commit to a £100k+ in-house CSO hire. Common scenarios: B Corp or post-IPO companies under investor scrutiny, founder-led businesses scaling, PE-backed portfolio companies preparing for exit.
How is advisory priced?
Monthly retainer. Lite (1 day/month, quarterly board attendance): £3,500/month. Standard (2 days/month, all board meetings, on-call): £7,000/month. Full fractional CSO (4 days/month, embedded with exec team): £14,000/month. 6 or 12-month contracts.
What does an advisor actually do?
Attends your board with prepared materials. Answers your CEO's hard questions. Reviews external statements for greenwashing risk. Briefs you when regulations move. Sense-checks consultant deliverables. Supports investor due-diligence calls. Designs your hire plan when you're ready for an internal CSO.
How is advisory different from consultancy?
Consultancy is project-based (fixed scope, fixed duration). Advisory is relationship-based (recurring, broad, lower intensity). Most clients use both: consultancy to build something specific, advisory to keep it pointed in the right direction year after year.
Related Services
Consultancy
Time-bound, project-based engagements. Materiality, baseline, framework readiness, supplier programme design.
Learn moreManaged Service
Ongoing operational outsourcing. We run ESG:ONE on your behalf with data, supplier and disclosure deliverables.
Learn moreESG:ONE Platform
The data, reporting and decision-intelligence software our advisors run on behind the scenes.
Learn morePut senior ESG counsel on your board, this quarter.
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