CharityIQ vs Plinth vs Undercroft vs FundRobin: Honest 2026 Comparison
Four sector-specific AI tools for UK charities compete in the same market in 2026, and the best choice depends on the charity's needs, as each serves a different niche. Starting prices vary widely: Plinth offers a free tier, Undercroft is bespoke and can run to thousands of pounds, FundRobin starts at £15/month, and a fourth platform starts at £49/month with a free grant finder. The tools differ across grant writing, compliance, impact reporting, case management and audit trail.
At a glance — feature and price matrix
| Capability | Plinth | Undercroft | FundRobin | CharityIQ |
|---|---|---|---|---|
| Starting price | Free tier | Bespoke (£thousands) | £15/mo | £49/mo (free Grant Finder) |
| Free tier | ✓ | ✗ | 30-day trial only | ✓ Grant Finder |
| Self-serve onboarding | ✓ | ✗ | ✓ | ✓ |
| Grant matching | ✓ | ✓ | ✓ | ✓ |
| AI grant writing | ✓ | ✓ | ✓ (Smart Proposal) | ✓ |
| Compliance / Annual return | Partial | ✓ | ✗ | ✓ |
| Impact reporting | ✓ | ✓ | ✗ | ✓ |
| Case management | ✓ (strong) | Partial | ✗ | ✗ |
| Multi-site support | ✓ | ✓ | ✗ | ✗ |
| Bookings + payments | ✓ | ✗ | ✗ | ✗ |
| Audit trail | Partial | ✓ | ✗ | ✓ |
| UK-hosted data | ✓ | ✓ | ✓ | ✓ |
| Founded by sector insider | ✓ | ✓ | ✗ | ✓ |
The matrix shows the structural difference. Each tool solves a different problem.
Plinth — what it does well, where it doesn’t fit
Founded: Long-established UK sector tool.
Pricing: Free tier for small charities. Paid tiers exist (specific pricing not publicly listed — request demo).
Coverage: Case management, AI grant writer, AI case notes, impact reporting, bookings, payments, multi-site support, volunteer management.
What Plinth does well:
Plinth’s superpower is breadth. For an advice charity supporting people through complex casework — domestic abuse, housing, immigration — Plinth handles client records, case notes, outcome tracking, AI summarisation, and impact reporting in one platform. Few competitors come close on this scope.
The free tier removes the price barrier completely for small advice charities, which historically have been the worst-served by sector software. Plinth’s “Complete Guide to [X] for UK Charities” content series is comprehensive — they’ve genuinely invested in helping the sector understand its own software needs.
Their AI grant writer is good. AI case notes is particularly clever — it structures advisor session notes into compliant casework records.
Where Plinth doesn’t fit:
Plinth is generalist by design. If your charity’s primary work is fundraising — applying to multiple grants per year, tracking applications, reporting impact to funders — Plinth’s depth on grants specifically is less than tools focused there. The compliance module is partial, not as deep on Charity Commission specifics or SORP 2026 detail.
For a small charity that doesn’t run a service-delivery operation needing case management, much of Plinth is unused weight.
Undercroft — what it does well, where it doesn’t fit
Founded: Spectrum Dynamics CIC.
Pricing: Setup fee + monthly. Bespoke. “Talk to us” — no public pricing tiers. Pricing position implies several thousand pounds setup plus ongoing.
Coverage: 9 named “agents” — Grant Scout, Bid Writer, Impact Reporter, TAR Drafter, Donor Steward, Comms & Social, Volunteer Coordinator, Fraud Radar, SORP Compliance.
What Undercroft does well:
Undercroft is the highest-governance option in the UK charity AI market. Self-hosted AI agents on UK servers. Audit trails on every action. Human approval workflows by default. Each charity’s deployment is custom — your data is kept completely separate from every other client.
Born from Spectrum Dynamics CIC — meaning the founders run a CIC themselves and understand sector operations from the inside. Their messaging is sober and trust-focused: charity-sector founders aren’t a tech vendor looking in.
For a £1m+ charity with sensitive beneficiary data, complex compliance, and willingness to invest in setup, Undercroft is a serious option. The 9-agent architecture covers nearly every charity admin function in one cohesive deployment.
Where Undercroft doesn’t fit:
The bespoke pricing model is the obvious limiter. There’s no realistic Undercroft offering for charities under £500k income. The implied pricing range (several thousand setup + ongoing monthly) is a serious commitment.
Self-serve onboarding doesn’t exist. Sales cycles are consultative — slower for charities that just want to test something quickly.
The website is a single page with no public feature documentation, which makes initial evaluation harder than competitors with self-serve product tours.
FundRobin — what it does well, where it doesn’t fit
Pricing: From £15/month. 30-day free trial. No per-seat fees.
Coverage: AI grant matching, AI proposal writing (“Smart Proposal”), 5,000+ UK funders in database.
What FundRobin does well:
FundRobin is the price-leader in UK charity AI. £15/month is a meaningfully different price point from CharityIQ’s £49 entry, Plinth’s paid tiers, or Undercroft’s bespoke pricing.
The product is focused — grant matching plus AI proposal writing. They claim “Smart Proposal saves 75% of writing time” and the underlying funder database is solid (5,000+ UK funders). GDPR compliant. UK-focused.
For a charity that genuinely only needs grant work — no compliance, no impact reporting, no case management — FundRobin is the most cost-effective option in the market.
Where FundRobin doesn’t fit:
The narrow scope is the trade-off. FundRobin doesn’t handle Charity Commission compliance, SORP 2026 reporting, impact measurement, or any non-grant workflow. If you need those things, you’ll need other tools alongside.
Brand presence is smaller than the others. Less sector-track-record visible publicly. Less customer-base information available.
For charities applying to grants regularly and needing compliance support, paying for both FundRobin and a separate compliance tool ends up similar in price to CharityIQ Growth tier (£149/mo) which integrates both — but with less workflow continuity.
CharityIQ — what we built and why (founder transparency)
Pricing: £49 (Starter) / £149 (Growth, most popular) / £349 (Professional) per month. Free Grant Finder forever. 14-day free trial on paid tiers.
Coverage: AI grant writing (grounded), Charity Commission compliance (annual return + SORP 2026 tier-aware), impact measurement, free Grant Finder, audit trails by default, UK-hosted data.
What CharityIQ does well (from the inside):
I built CharityIQ specifically for UK charities with annual income £25,000–£500,000 — the band where most small charities live and where existing tools were thinnest. Three things distinguish what we do:
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Grounded AI. Every output cites your charity’s verified data. Charity Commission profile, your beneficiaries, your past applications, your funder database. No invented statistics. Every fact has a source one click away.
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Integrated workflow. Grant writing, compliance, and impact in one platform — not three. Your grant applications cite your impact data; your impact reports use the outcomes from your grant work; your compliance module knows what you’ve reported. The integration matters when you’re a small team doing all of these.
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Self-serve and fairly priced. £49/£149/£349 monthly tiers. Free Grant Finder forever. 14-day free trial, no credit card. You can sign up at 11pm and try the product yourself. No sales call required.
Where CharityIQ doesn’t fit:
I’ll be direct. We’re newer than Plinth or Charity Excellence Framework. Our customer base is growing but smaller than incumbent tools. If extensive third-party customer reviews matter to you, we’re earlier on that journey.
We don’t do case management or bookings. If your charity’s primary work is service delivery requiring client records, Plinth is structurally better suited.
We don’t do bespoke deployments. If you want custom AI agents shaped to your specific workflow, Undercroft is the right choice (and likely worth the premium pricing for charities that need it).
If you’re a charity with annual income under £25,000 and only need help with one-off grant applications, even our Starter tier may be more than you need — Charity Excellence Framework’s free AI Bunny is a sensible starting point.
From CharityIQ
Full disclosure again: this comparison is published by us. We’ve tried to be fair to every tool — including admitting where we’re not the right fit.
If your charity has 2+ grants/year, runs Charity Commission compliance, and wants impact reporting in one tool — that’s exactly what we built CharityIQ for. Start free 14-day trial.
Pricing in detail
The four tools have meaningfully different commercial models. Worth understanding before deciding.
| Aspect | Plinth | Undercroft | FundRobin | CharityIQ |
|---|---|---|---|---|
| Free tier | Yes (small charities) | No | 30-day trial | Yes (Grant Finder) |
| Entry paid tier | Private pricing | Bespoke | £15/mo | £49/mo |
| Mid tier | Private | Bespoke | — | £149/mo |
| Top tier | Private | Bespoke | — | £349/mo |
| Setup fee | None | Yes (significant) | None | None |
| Per-seat pricing | Varies | N/A | None | None |
| Annual discount | Likely | Negotiated | Likely | 20% (£39/£119/£279) |
Hidden costs to watch:
- Plinth’s free tier eventually hits paid features for AI access
- Undercroft’s setup fee is real; budget for several thousand pounds before monthly fees begin
- FundRobin at £15/mo is genuinely affordable but lacks compliance and impact — you’d need other tools (cost stacks)
- CharityIQ’s free Grant Finder is forever — only paid if you want AI drafting / compliance / impact
For a £100k charity needing grants + compliance + impact, the realistic comparison is CharityIQ Growth (£149/mo) versus Plinth paid + supplementary compliance tool versus FundRobin + separate compliance tool. The integrated single-platform approach is usually simpler.
A decision tree by charity size and need
| Your situation | Recommended tool |
|---|---|
| Under £25k income, one-off bids | Charity Excellence AI Bunny (free) |
| £25k–£100k, grants + compliance | CharityIQ Starter or Growth |
| £100k–£500k, multi-tool integrated workflow | CharityIQ Growth |
| £500k+, multi-user, trustee dashboard | CharityIQ Professional |
| Advice charity, case management heavy | Plinth |
| Multi-site charity | Plinth (multi-site) or Undercroft |
| Service delivery + grants + bookings | Plinth |
| £500k+ wanting custom AI agents | Undercroft |
| Grant matching only, tight budget | FundRobin |
| Beginner with no fundraising team | Charity Excellence AI Bunny |
| Generic admin and drafting | ChatGPT (free) |
When you might want two tools, not one
Many UK charities end up with overlapping tooling. Some patterns work:
Plinth + CharityIQ: Service-delivery charities use Plinth for case management and impact, plus CharityIQ for grants and compliance. Different workflows, different tools.
Charity Excellence AI Bunny (free) + paid sector tool: Use AI Bunny for one-off bids when you’re learning, plus the paid tool for ongoing work. Cost-effective on-ramp.
FundRobin + separate compliance: Tight-budget charities use FundRobin for grants and a separate (cheaper or in-house) approach for compliance. Cost-stacks but works.
ChatGPT alongside any sector tool: Generic AI for drafting communications and brainstorming, plus the sector tool for fundraising/compliance. Most charities end up with this combo.
The “one tool to rule them all” doesn’t really exist. Picking the right tool for your primary workflow, and supplementing as needed, is the realistic pattern.
What to do next
If you’re choosing between these four tools, the practical move is to try them. Free tiers and free trials remove the cost barrier:
- CharityIQ free trial (14 days, no credit card)
- Plinth free tier
- FundRobin free trial (30 days)
- Charity Excellence Framework AI Bunny (free)
Test each on a real task — drafting a grant application or generating an impact report. Time it. Compare outputs. The tool that feels best for your workflow within an hour of trying is usually the right one.
For charities that fit our specific profile (£25k–£500k income, multiple grants, compliance + impact integrated), CharityIQ is what we built. The 14-day free trial is exactly long enough to compare honestly.
Try the integrated option free.
CharityIQ 14-day trial — no card required.
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Frequently asked questions
Depends on what you need. For broader scope (case management, bookings, payments): Plinth. For lower price (grant-only): FundRobin. For bespoke high-governance: Undercroft. For free: Charity Excellence Framework AI Bunny.
For service-delivery charities (advice, case management): Plinth. For grant-focused fundraising charities under SORP 2026: CharityIQ. Both have free tiers worth trying.
FundRobin is cheaper for grant-only use (£15/mo vs CharityIQ’s £49 entry tier). CharityIQ becomes cost-comparable when you need compliance and impact integrated, since FundRobin requires separate tools for those. For a £100k charity needing grants + compliance + impact, CharityIQ Growth (£149) is competitive with FundRobin + separate tools.
For charities £500k+ income with sensitive beneficiary data, complex compliance needs, and willingness to invest several thousand pounds in setup. The custom AI agents shape to specific workflows in ways self-serve tools don’t.
Yes — many UK charities do. Plinth + CharityIQ is a common pattern. ChatGPT alongside any of them is normal. The integration story across tools is imperfect (each is its own platform), but the overlap is manageable.