£79. Not £2,000.
HMRC-ready in under an hour. No lawyers. No accountants. No monthly plans. Built by the founder of the UK's first SEIS fund.
Takes 5 minutes. No account needed.
SEIS advance assurance — what others charge
Save over £300 vs SeedLegals. Save £1,900 vs a professional.
Why trust us
“Built by the founder of the UK's first SEIS fund in 2012. Not an AI consultancy that built this as a side project. Someone who has sat on both sides of the table: as the fund writing the cheques, and as the person helping founders get ready to receive them.”
We have been in this world since 2012. We know what HMRC looks for, what trips founders up, and why paying thousands of pounds for a form-filling exercise never made sense. Seisly fixes that. And because we have spent over a decade doing this for real, we handle the complex cases that other tools cannot.
How it works
We handle the complexity. You focus on building.
Answer a few questions about your company and we check you against all HMRC qualifying conditions for SEIS and EIS. Free, instant, and no account needed.
Takes 5 minutesHow much are you raising, from how many investors, and on what terms. We use this to complete your application correctly first time.
No jargon, plain English throughoutOur AI generates your full advance assurance submission, including the covering letter HMRC expects, built from over a decade of real applications.
AI-powered, expert-trainedRead through your application, make any tweaks, and submit directly to HMRC's SEIS and EIS team. We track the status and alert you to any updates.
HMRC turnaround: 4 to 8 weeksOnce approved and shares are issued, generate SEIS3 or EIS3 certificates for every investor in one click. Ready to send straight away.
Included in your one-off feeWhat is included
One flat fee covers the entire SEIS or EIS journey, start to finish.
Know in 5 minutes whether you qualify, before you spend a penny.
A proper covering letter drafted to HMRC's expectations, trained on a decade of real applications.
All required HMRC forms completed and formatted correctly. Nothing left blank.
SEIS3 and EIS3 certificates generated automatically once HMRC approves and shares are issued.
We track your 3-year compliance window and alert you when action is needed.
If HMRC writes back with questions, we help you respond. Included, not billed by the hour.
The honest comparison
We are not the only option. We are just the best one.
| Lawyers and accountants | SeedLegals | Seisly ✦ | |
|---|---|---|---|
| SEIS advance assurance | £2,000+ | £399 + plan | £79 |
| EIS advance assurance | £2,500+ | £799 + plan | £129 |
| SEIS and EIS together | £3,000+ | £999 + plan | £149 |
| Investor certificates included | ✗ | ✓ | ✓ |
| No monthly subscription | ✗ | ✗ | ✓ |
| Instant eligibility check | ✗ | ✓ | ✓ |
| Complex cases handled | ✓ | ✗ | ✓ |
| HMRC query support included | ✗ billed extra | ✗ | ✓ |
| Compliance tracking included | ✗ | ✗ | ✓ |
| Built by SEIS fund founders | ✗ | ✗ | ✓ |
| Money-back guarantee | ✗ | ✗ | ✓ |
Pricing
Pay once per application. No subscriptions, ever.
FAQ
Seisly done. £79.
Join the founders who skipped the lawyers and accountants,
saved thousands, and got investor-ready faster.
Takes 5 minutes. No credit card needed to check eligibility.