Comparison
FounderCatalyst papers your whole raise on an annual subscription with advance assurance included. Seisly prepares advance assurance on its own, one payment, no subscription. Here is an honest comparison of when each is the better buy.
| Seisly ✦ | FounderCatalyst | |
|---|---|---|
| Advance assurance price | £99 prepared, or £399 fully done for you | Included, but only within a plan or product |
| Can you buy advance assurance on its own? | Yes | No |
| Cheapest total for one advance assurance | £99 | £995 (LaunchPad, raises under £100,000) |
| Subscription required | None | Yes – LaunchPad £995/yr, Core £1,995/yr, Accelerate £2,995/yr |
| Individual products | Not applicable | £1,450 each (ASA, priced round, agile round) |
| Percentage-of-raise fees | None | None |
| What you get | Advance assurance, prepared and submitted | Round legals, advance assurance, compliance, cap table, options |
| Specialist SEIS/EIS focus | Sole focus | One component of a fundraising platform |
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Prices verified against seisly.com and foundercatalyst.com, 24/07/2026.
Seisly charges £99 for the application prepared and ready for you to file, or £399 for the full service including human review and submission to HMRC.
FounderCatalyst does not sell advance assurance separately. It is included across their plans – LaunchPad at £995 a year for raises under £100,000, Core at £1,995 a year with no cap, Accelerate at £2,995 a year adding option schemes – or within individual products priced at £1,450 each. So the cheapest route to a FounderCatalyst advance assurance is the £995 annual subscription.
Both are fixed-price and neither charges a percentage of what you raise. The difference is scope and commitment: FounderCatalyst is an annual subscription covering a whole raise; Seisly is a one-off covering one application.
If you are papering a full round this year – investment agreement, articles, compliance, cap table, option schemes – FounderCatalyst covers all of it on one annual fee with no percentage on the raise. Advance assurance comes with it.
If you need advance assurance now – to test investor appetite, because you are very early, or because the round itself is being handled elsewhere – Seisly prepares it for £99, or £399 fully done for you, rather than a £995 annual subscription for a platform you are not yet using. No annual commitment, and nothing to cancel.
And Seisly is not standing still at advance assurance. Cap table, fundraising document templates and investor outreach are arriving through this year, building toward support across the whole raise – and Seisly already connects founders with law firms and advisers who work on fixed, competitive fees for the work that needs a regulated firm.
FounderCatalyst is for founders running a full raise this year who will use the whole platform from the start.
Seisly is for founders who need advance assurance done properly now – from a specialist that is building outward across the raise this year, with an adviser network already in place for regulated work – rather than committing to a full annual platform subscription up front.
A lawyer is for genuinely complex or bespoke structures, or where an investor requires formal advice.
No. It is included within their plans rather than sold separately, so the cheapest route is the £995 a year LaunchPad subscription. Seisly prepares advance assurance on its own from £99.
For advance assurance on its own, yes – £99, or £399 fully done for you, against a £995 annual subscription. They are not like-for-like: FounderCatalyst's fee covers a whole raise. For the application alone, Seisly is the cheaper route.
FounderCatalyst is an annual subscription covering your raise, with advance assurance included. Seisly does one thing: prepare, and optionally submit, your advance assurance application, for a one-off fee. Different scope, both fixed price.
FounderCatalyst – that is what it is built for. Seisly is the specialist for the advance assurance step.
Seisly drafts from a short questionnaire, usually under an hour. HMRC then typically takes 4 to 8 weeks, whichever route you use.
Figures verified against seisly.com; foundercatalyst.com, 24/07/2026. Competitor prices and HMRC thresholds are taken from primary sources, not from either party's marketing about the other.
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