Charity Impact Frameworks Compared 2026: NPC vs IRIS+ vs Outcomes Star

Charity Impact Frameworks Compared: NPC vs IRIS+ vs Outcomes Star (2026)

Three of the most-used impact measurement frameworks in the UK charity sector — what each does, where each fits, and how to pick.

Last reviewed: 08/06/2026 · By Ivan Siyanko, CEO, CharityIQ.

TL;DR. NPC Four Pillars — UK sector’s plain-English starting framework. Outcomes Star — used by 4,000+ UK organisations to track individual service-user progress. IRIS+ — international impact-investing standard. You don’t have to pick one — many UK charities use NPC strategically and Outcomes Star operationally.

Why frameworks matter

Under SORP 2026, every UK charity must include impact narrative in their Trustees’ Annual Report. Funders read impact reports more carefully than ever. Without a framework, charities tend to track outputs (sessions delivered, people reached) and call it impact. Frameworks force the harder question: what changed for beneficiaries because of our work?

1. NPC’s Four Pillar Approach

Best for: charities new to impact measurement. Cost: free. Source: NPC — UK’s leading sector think tank on impact.

Strategic approach organised around four pillars: (1) Theory of Change (see our template), (2) Measurement framework, (3) Reporting and learning, (4) Embedding across the organisation.

A meta-framework: tells you how to think about impact, not exactly what to measure. Strengths: plain English, UK-context, free guidance including Theory of Change in Ten Steps, used by NCVO, IVAR, major UK funders. Limitations: doesn’t give off-the-shelf metrics; requires charity to do its own thinking. Best fit: small UK charities (£25k–£500k income).

2. Outcomes Star

Best for: charities providing direct, ongoing service to individual beneficiaries. Cost: licensed (£100–£500/yr for small charities). Source: Triangle Consulting — UK-based.

Structured tool for measuring change in individual service users across multiple life domains. 30+ Star versions: Homelessness Star, Recovery Star, Family Star, Older Person’s Star, Mental Health Recovery Star, Youth Star, etc. User plots progress on 1-10 scale across each domain; repeat at intervals; chart shows movement.

Used by: 4,000+ UK organisations. Strengths: co-produced with beneficiary, validated, visual, aggregates well. Limitations: licensed cost, best for ongoing key-worker-led services, requires staff training. Best fit: mid-sized UK charities (£100k+) running direct services.

3. IRIS+

Best for: charities engaged with social investors. Cost: free. Source: Global Impact Investing Network (GIIN).

Catalogue of standardised metrics for social, environmental, financial performance. Aligns with SDGs, Five Dimensions of Impact, B Corp. 600+ specific metrics organised by sector. The point is standardisation: apples-to-apples comparison.

Strengths: free, international recognition, comprehensive, aligns with major standards. Limitations: designed for impact investors first; less narrative, more numbers; needs UK-specific interpretation. Best fit: UK charities receiving social investment, social enterprises, charities with international operations.

How they fit together

Layer	Framework	Question it answers
Strategic frame	NPC Four Pillars	How do we think about impact?
Operational measurement	Outcomes Star	How do we track individual change?
External reporting	IRIS+	How do we report comparably to investors?

For a £200,000 small UK charity, NPC’s framework alone is usually enough. As the charity grows or engages with social investment, Outcomes Star or IRIS+ add layers.

Other UK frameworks worth knowing

PQASSO/Trusted Charity — quality management from NCVO. Theory of Change — methodological tool inside NPC’s first pillar. LFA — international development. Quality Mark Programmes — sector-specific.

How to choose

Five questions: (1) impact maturity stage; (2) service model — direct service / programme / social investment; (3) beneficiary group; (4) capacity; (5) who’s asking — funders rarely mandate; institutional like clear theory of change + outcomes (NPC satisfies); social investors increasingly want IRIS+.

Most small UK charities I work with land at: NPC framework as strategic frame + custom outcomes set in spreadsheets. Layer Outcomes Star or IRIS+ as you grow.

From CharityIQ. Supports any framework — NPC, Outcomes Star, IRIS+, or custom. Pick your frame, define outcomes, capture data once. Reuse across every grant report. See impact reporting →

Mistakes to avoid

1. Picking wrong framework first. Small charity adopting IRIS+ on day one will drown. 2. Confusing framework with tool. Framework tells you how to think; tool what to capture. 3. Reporting at framework level, measuring at metric level. Pick 5 outcome statements that matter. 4. Switching every two years. Commit 3 years minimum. 5. Treating impact as compliance. Frameworks shape decisions, not just year-end reports.

FAQ

Q: Outcomes Star affordable for small charity? Yes, £100-£500/year if running direct service. Q: IRIS+ for small grant-funded charities? Probably not as primary. Use only if funder asks. Q: SORP 2026 interaction? Whichever framework, narrative should explain what changed for beneficiaries. NPC lends itself naturally. Q: Funder preference? Most don’t mandate; want clear thinking, specific outcomes, honest reporting. Q: Where do I start? Read NPC’s Theory of Change in Ten Steps; draft yours; derive 3-5 measurable outcomes. Built in 2 days.

What to do next

1. Read NPC’s Four Pillars guidance. 2. Draft a theory of change — use our free template. 3. Pick 3-5 outcomes for next 12 months. Don’t over-engineer.

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Written by Ivan Siyanko, founder of CharityIQ.

Sources: NPC — Measurement Framework · Outcomes Star · IRIS+ · Small Charities — Impact