The moment your UK company grants share options to someone who pays US tax, those options fall under IRS pricing rules. An HMRC EMI valuation does not satisfy Section 409A, so UK companies with US optionholders need to meet both regimes at once.
Expanding into the United States is a milestone. But whether you have hired a US engineer, done a Delaware flip or closed a round with US investors, you now need a supportable US valuation of your ordinary shares. That is what a 409A valuation provides, and why the basics of 409A safe harbor matter more for UK founders than most realize.
The short answer: A 409A valuation is an independent appraisal of the fair market value of your common (ordinary) shares, in US dollars. Granting options to US taxpayers at or above that value, using an independent appraisal less than 12 months old with no material change since, gives the grants safe harbor protection: if the IRS challenges the value, it must show it was grossly unreasonable. An HMRC EMI valuation does not provide this.
Key takeaways
- US holders trigger 409A: options for any US taxpayer, whether an employee, contractor or advisor, bring the grant under Section 409A.
- EMI is not 409A: the two regimes differ on method, time limits and discounts; you usually need both.
- 12 months at most: a 409A supports grants for up to 12 months, or until a material event such as a priced round or a Delaware flip.
- The employee pays: a failed grant means tax on vested options, a 20% additional federal tax and interest.
- Cross-border work is harder: sterling financials, UK accounting, UK share classes and group structures all need care.
Do You Need a 409A? Four Triggers for UK Companies
If any of these apply, you almost certainly need a US valuation, even if your company never leaves the UK. If you are unsure, a quick review by our 409A valuation service will confirm your position.
| Trigger | Why it matters |
|---|---|
| You hire US-based staff or advisors | Granting options to someone who pays US tax brings those options under Section 409A, even if the company stays wholly in the UK. Without a supportable US valuation, the US holder can be taxed on vested options plus a 20% additional federal tax. |
| You do a Delaware flip | A new Delaware C corp becomes the parent and the UK company becomes its subsidiary. Equity granted to US holders from then on is over the US parent's shares and needs a 409A valuation. The flip itself is usually a material event, and UK staff may lose access to EMI unless the new structure still qualifies, so plan both sides with your advisers. |
| You raise from US investors | A priced round sets a new preferred share price, which almost always changes the value of the common shares. Options granted after the round need a valuation that reflects it. |
| You set up a US subsidiary | If your US team receives options over the UK parent's shares, those options need a 409A-supportable value for the UK shares, in US dollars. A UK valuation prepared for HMRC does not provide it. The US subsidiary will also have its own US filings, including Form 5472 if it is 25% or more foreign-owned. |
409A vs HMRC EMI: Why One Valuation Won't Cover Both
A common and costly mistake is assuming that an HMRC agreed EMI valuation also satisfies the IRS. It does not. Both look for the market value of ordinary shares, but they differ on method, timing and what happens when the price is wrong. A UK company with US optionholders has to satisfy both.
| HMRC EMI (UK) | IRS Section 409A (US) | |
|---|---|---|
| Purpose | Agree the market value of shares for EMI options with HMRC | Support a US option strike price at or above fair market value |
| Can options be granted below market value? | Yes. EMI options can be granted at a discount; the discount is taxed when the option is exercised | No. Options priced below fair market value are discounted deferred compensation |
| How long the value lasts | An HMRC agreed value generally covers grants within 90 days | An independent appraisal supports grants for up to 12 months, unless a material event happens first |
| Is agreeing the value required? | Optional, but most companies agree it with HMRC before granting | An independent appraisal is optional, but it gives the safe harbor presumption |
| Who bears the cost of getting it wrong | The employee can lose EMI tax advantages and pay income tax (and possibly National Insurance) on exercise | The US optionholder: tax as options vest, plus 20% additional federal tax and interest |
| Regulator | HMRC | IRS |
The cost of a 409A failure falls almost entirely on the optionholder: tax as the options vest rather than at exercise, a 20% additional federal tax, and interest at the IRS underpayment rate plus 1 percentage point. CSOP options, like 409A options, must be granted at no less than market value, but a CSOP valuation agreed with HMRC still does not give IRS safe harbor. For more on how the US penalties work, see our 409A valuation guide.
What Makes a Cross-Border Valuation Harder
Valuing a UK company for US purposes involves issues a US-only startup never meets. Each is a place where automated tools and generalist providers tend to struggle.
- Currency: sterling financial statements and share prices must be translated into US dollars at the valuation date.
- Accounting differences: UK companies report under FRS 102 or IFRS. The IRS does not require a restatement to US GAAP, but the appraiser must understand differences, such as revenue recognition or capitalized development costs, that change how the numbers compare with US peers.
- Comparable companies: the appraiser has to choose public companies and transactions, in the US and elsewhere, that genuinely match your market and stage.
- UK share structures: EIS and SEIS investors must hold ordinary shares without preferential rights on a winding up, so UK cap tables often mix EIS ordinary shares with VC preference shares. The rights of each class, set out in the articles of association, must be modeled carefully.
- Group structure: after a flip or with a US subsidiary, the valuation must reflect which entity’s shares are being granted and how value sits across the group.
Cross-border details are where valuations get questioned.
Let a team that works on UK and US structures handle the mechanics.
Why Automated 409A Platforms Struggle with UK Companies
Automated valuation platforms are generally built for simple, US-only Delaware C corps. They are not designed for sterling financials, UK share classes or a UK parent with a US subsidiary, so the inputs and method may not fit your structure, which weakens the valuation if it is ever questioned. Our 409A cost comparison looks at software and expert valuations side by side.
| Automated software | Countsure | |
|---|---|---|
| Cross-border structures | Built mainly for simple US-only Delaware C corps | Analysis of UK and US share classes, currencies and group structure |
| Safe harbor | Depends on the inputs and on whether the method suits your structure | Prepared as an independent appraisal to meet the safe harbor conditions |
| Auditor review | Assumptions can be thin when an auditor or buyer asks questions | Full report that sets out methods, assumptions and data so reviewers can follow them |
| Financial data | Relies on numbers the founder enters | Financials reviewed and adjusted by CPAs and Chartered Accountants |
| Support | Support tickets and chat | Direct access to the senior valuer on your engagement |
How Countsure Delivers for UK Startups
Countsure’s team of CPAs, Chartered Accountants and CMAs works on international tax and valuation every day. We take the stress out of cross-border equity so you can keep hiring and raising on schedule.
- Fully documented reports: methods, assumptions and data set out so auditors, investors and acquirers can follow them. See a sample 409A valuation report.
- Credentialed appraisers: led by a US CPA and Registered Valuer who has valued companies at your stage.
- Both sides covered: we work alongside your UK advisers on EMI and with your US team on the US subsidiary’s filings, such as Form 5472.
Secure Your Cross-Border Equity Today
Issuing equity to US talent is a major step for a UK company, and an unsupportable valuation can leave your team with serious US tax bills. Don’t let a compliance gap slow your US expansion. Work with Countsure to get the US side right from the first grant.
Frequently Asked Questions
1. Does a UK company need a 409A valuation?
Only if it grants options, or similar rights, to people who pay US tax, such as US-based employees, contractors or advisors, or if it has flipped to a US parent. Options for UK-only staff are governed by UK rules, though anyone who later moves to the US can come under Section 409A.
2. Does an HMRC EMI valuation satisfy IRS 409A?
No. Both look for market value, but they are separate rules with different methods and time limits, and EMI allows options below market value while 409A does not. An EMI valuation does not give IRS safe harbor, so US optionholders need a separate 409A valuation.
3. Can I use an automated 409A platform for my UK startup?
It is risky. Most platforms are built for simple US Delaware C corps. They are not designed to deal with sterling financials prepared under FRS 102, UK share classes such as EIS-qualifying ordinary shares alongside preference shares, or group structures with a UK parent, so the valuation may not hold up if it is questioned.
4. How often does my UK company need a 409A refresh?
At least every 12 months while you keep granting US options, and before the next grant after any material event. For UK startups, typical material events are a priced round with US or UK investors, a Delaware flip, or a large change in revenue.
5. What happens if we grant options to US employees without a proper valuation?
If the strike price turns out to be below fair market value, the IRS treats the options as non-compliant deferred compensation. The US optionholder can be taxed on the vested options as they vest, plus a 20% additional federal tax and interest, even before exercising.
6. How much does a cross-border 409A cost?
Countsure charges a fixed fee, confirmed before the engagement starts. It depends on how complex your cap table, share classes and funding history are, and on whether there is a US subsidiary or a flipped structure to value.
7. How long does the valuation take?
Once we have the data room (Companies House filings, cap table, articles of association, financial statements and projections), we confirm a delivery timetable at engagement. Clean data and a simple share structure make it faster.
Related Countsure Blogs
- 409A Valuation Guide: costs, penalties and safe harbor explained.
- 409A Safe Harbor Guide: how the presumption of reasonableness works.
- When Is a 409A Valuation Required?: the events that trigger a refresh.
- Stock Options and 409A for Employees: a guide to share with your US team.
Parth Shah, Managing Director
(CPA-US, FCA, RV-S&FA, DISA)
Parth Shah who is head of Accounts and Book keeping has experience of more than 10 years. A Certified Public Accountant – US, fellow Chartered Accountant, Registered Valuer and Diploma in Information System Audit.
