A secondary or tender offer is often the first time a startup employee or early investor turns paper equity into real money — and the first time a large tax bill lands. You are not selling the whole company; you are selling a slice of a company that is still private and still operating, to an incoming investor or back to the company itself. If you sell while you are tax resident in a high-tax country, the gain is taxed there — sometimes at rates that swallow a third or more of it. The quieter move is to make a genuine, well-timed relocation before the deal closes, so the gain can fall into a low, defined regime instead. Bulgaria is one of the cleanest landings: 10% flat personal income tax, 15% combined for a company, inside the EU. This guide explains how secondaries, tender offers and buybacks differ, how 409A valuation and ISO/NSO/RSU treatment interact, the honest limits — including US citizenship-based taxation and why private pre-IPO shares are taxed, not exempt, in Bulgaria — and exactly when the residence has to be in place.
Sitting on a secondary or tender offer you expect to close this year? The costly mistake is treating residence as something to sort out after the money hits your account. The gain crystallises when the deal settles — so the planning that matters happens before that date, while you are still deciding where you are tax resident. Once the shares are sold, the position is fixed.
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Innovires structures relocations into Bulgaria for founders, startup employees and early investors — residency, company setup, treaty analysis and first-year compliance.
Secondary Sale, Tender Offer or Buyback — What You Are Actually Selling
All three let you take illiquid private equity off the table before an IPO, but they are not the same transaction, and the differences matter for both timing and tax:
- A secondary sale — you, as an existing shareholder, sell your private shares directly to a new buyer: a growth fund, a secondary-market platform buyer or another investor. The company does not issue new stock; ownership simply moves from you to them.
- A company tender offer — the employer organises a fixed-price buyback of employee and early-investor shares, usually syndicated to incoming investors who take the shares onto their own books. It is the structured, company-blessed version of a secondary, run to give the whole cap table some liquidity at once.
- A buyback — the company itself repurchases shares from shareholders, retiring them or holding them, rather than routing them to an outside investor.
In every case the person selling is an employee, early investor or angel disposing of a slice of a company that stays private and keeps operating. That is the defining feature of this article — and the pivot point for the whole tax question below.
This is not a founder trade sale — and the distinction is the point. When a founder sells the whole company, control passes to a buyer in a negotiated, diligenced, usually large one-off deal. Here you sell a fraction of a company that carries on without you, often at a price anchored to a 409A valuation and on someone else's timetable. The tax logic of getting your residence right before the gain crystallises is identical — but the mechanics, the constraints and the size are different. If you are selling the entire business, our relocating before selling your company guide is the one built for that, and founders should read it alongside this.
Why the Timing of Your Residence Decides the Tax
A capital gain is generally taxed by the country where you are tax resident on the day the gain crystallises — the day the sale closes. Sell your pre-IPO shares while you are still resident in a high-tax country and the gain is taxed there, on that country's terms. Become genuinely tax resident somewhere with a low, defined regime before the deal settles, and the gain can fall into that regime instead. Nothing about the shares changes; only your tax home does.
For a startup employee or angel, the numbers are rarely small. A secondary or tender offer is frequently the moment years of illiquid upside becomes a single realised gain — and a single realised gain is exactly the kind of event where the difference between a high home rate and a 10% flat rate is measured in life-changing sums. That is why the timing of your Bulgarian residence is not a footnote to the deal; it is the deal's most valuable variable, and the one that closes first.
Not sure how large your gain — or your exposure — really is? Send us your holding, expected offer price and rough close timing — we map the exposure, free, in writing.
409A Valuation, ISOs, NSOs and RSUs — What Sets Your Gain
Before you can plan around a gain, you have to know how it is built. Two mechanics do most of the work:
The 409A valuation sets the price
A 409A valuation is the independent appraisal of a private company's common-stock fair market value. It sets the strike-price benchmark for options and, in practice, anchors what a tender offer pays. Tender prices are typically set at or near the current 409A value, and a large secondary can itself push the next 409A appraisal upward. For you it is simple but decisive: the offer price is your proceeds, your proceeds minus your cost or exercise price is your gain, and that gain is the number your residence then gets taxed on.
ISOs, NSOs and RSUs are taxed at different moments
How your equity was granted determines when tax already bit, and therefore how much of your secondary is a fresh capital gain versus compensation that was taxed earlier:
- RSUs generate ordinary income on the vest date — whether or not you sell. By the time you reach a secondary, much of that value may already have been taxed as compensation.
- NSOs create ordinary income on the spread at exercise (fair value minus strike), typically with payroll withholding.
- ISOs avoid ordinary income at exercise but can trigger US alternative minimum tax on the spread, with long-term capital-gains treatment on a later sale if the holding rules are met.
The planning consequence is that a secondary sale often mixes two very different pieces: a compensation element, usually tied to where you worked and earned it, and a pure capital gain on the eventual disposal. Relocation planning has to separate them — moving your residence changes the treatment of the capital gain far more cleanly than it changes compensation that was already earned and taxed in another country.
The Practical Constraints on When You Can Sell
Timing a move sounds simple until you remember you rarely control the sale date. Private shares come wrapped in restrictions, and each one moves the goalposts:
- Right of first refusal (ROFR) — the company or its major investors can match your buyer's offer, so even an agreed secondary carries a waiting window (commonly around 30 days) before it can actually close.
- Lock-ups — transfers are blocked for a defined period around a financing or, especially, an IPO. A lock-up does not create a matching right; it simply stops sales for the restricted window.
- Blackout windows and transfer approval — company policy and the board can gate when and to whom shares move.
- The 90-day post-termination exercise window — leave your job and, with many option grants, you have a short window to exercise or forfeit, forcing an equity decision on its own clock rather than yours.
Why the constraints make timing harder, not easier: because ROFR, lock-ups and blackout rules mean the close date is only partly in your hands, you cannot leave the residence to the last minute and hope to slot it in before settlement. The genuine Bulgarian residence has to be established well ahead of the expected close, with margin — so that whenever the deal actually lands, you are already, provably, resident.
What Bulgaria Actually Charges — 10%, Not Zero
Here is the honest core, and it is important to get it exactly right rather than oversell it. Bulgaria does exempt some share gains — but only a specific kind. Under Article 13(1)(3) of the Personal Income Tax Act (ЗДДФЛ), read with the definition in §1 item 11, the exemption covers disposals of financial instruments executed on an EU or EEA regulated market or growth market. Your pre-IPO shares are private and not listed on any regulated market — so that exemption simply does not reach them.
What that means for you is clear: the gain on a private secondary or tender offer is taxable in Bulgaria, at the 10% flat rate. Under Article 33(3) ЗДДФЛ, the tax is charged on the profit — your proceeds minus your acquisition cost or exercise price — not on the gross amount you receive. So it is 10% of the gain, not 10% of the whole cheque. Low and defined, but not nil. Anyone who tells you a private pre-IPO sale is tax-free in Bulgaria is misreading the exemption.
Why 10% on the gain is still the point. The exemption you do not get for private shares does not undo the value of the move. A departing seller who would face a high home-country rate on the same gain — often two, three or four times as much — reduces the charge to a flat 10% on the profit by being genuinely resident in Bulgaria when the deal closes. The saving is real precisely because the comparison is against a much higher home rate, not against zero.
Everything sits inside an EU member state that adopted the euro on 1 January 2026 and has been fully in Schengen since 1 January 2025 — not an offshore jurisdiction with no treaty network. If you would also run future consulting, advisory or angel activity through a company, a Bulgarian EOOD is taxed at 15% combined (10% corporate income tax plus 5% on dividends). Still deciding where to land? Our country-selection framework is the companion piece, and our Bulgaria tax residency guide covers the destination in full.
If You Are a US Person — the Honest Caveat
Much of this audience is US-based, and here the honesty has to be blunt: relocating does not, by itself, erase US tax. The United States taxes its citizens and green-card holders on worldwide income regardless of where they live — citizenship-based taxation. Move to Sofia and, if you remain a US person, you generally still file a US return and may still owe US tax on the gain, with the applicable treaty and foreign tax credits deciding how the two systems mesh rather than whether the US charge exists at all.
QSBS is a US-only benefit that may not travel. The Section 1202 Qualified Small Business Stock exclusion can shelter a large slice of gain on qualifying US C-corporation stock — but it is available only to taxpayers who are subject to US capital-gains tax. It is not a benefit a non-US-resident position extends or improves; a person outside the US tax net does not "gain" QSBS, and depending on your facts a QSBS position may be forfeited or simply not apply once your tax home changes. Never assume QSBS travels with you. If it is central to your plan, it has to be modelled with US counsel before anyone changes residence — this is a point to confirm, not to take on faith.
The practical upshot: relocation changes the tax picture most cleanly for people who are not US persons, or for US persons who understand precisely how the US charge, the treaty and any QSBS position interact and plan around that reality rather than wishing it away. For everyone in this audience, our moving to Bulgaria from the US guide sets out the American-specific mechanics, and angels weighing carried interest should read Bulgaria for angel investors and carried interest.
Want your exact position — home country, US status, QSBS, expected close — scoped in writing? We return a written relocation and timing plan in 48 hours.
Two Sales, Side by Side — Secondary Slice vs Whole-Company Exit
| Factor | Secondary / tender offer (this article) | Founder whole-company sale |
|---|---|---|
| What is sold | A slice of a still-private company | The entire company / control |
| Who sells | Employee, early investor or angel | Founder(s) / controlling owners |
| Company after the deal | Stays private, keeps operating | Changes hands to a buyer |
| Price setting | Anchored to 409A / offer price | Negotiated in the transaction |
| Control over timing | Limited — ROFR, lock-ups, blackout | Higher, but diligence-driven |
| Bulgarian tax on the gain | 10% flat on profit (not exempt — private shares) | 10% flat on profit |
| Timing principle | Be resident before close | Be resident before close |
The right-hand column is the founder trade sale — a different transaction with its own guide. The value of this table is the shared bottom two rows: whichever sale you are running, the Bulgarian charge is a flat 10% on the profit, and the residence has to be genuine and in place before the deal closes. What differs is everything above those rows — and that is why you should not treat a secondary like a whole-company exit, or vice versa.
Doing It Properly — Substance, Not a Last-Minute Move
The 10% only holds if the residence is real. Bulgarian tax residence turns on genuine facts under Article 4 ЗДДФЛ — the 183-day test or your centre of vital interests — and a gain this size will attract scrutiny, so the substance has to be there:
- A real home and life in Bulgaria — where you actually live, not merely an address. Establishing your centre of vital interests in Bulgaria is what makes the residency defensible if it is ever tested.
- A clean break from the former country — because exit taxes and trailing-residence rules in your old country can still claim the gain if your life never really left. A move that is real on the map but thin in substance is the worst of both worlds.
- Documented Bulgarian residence — a tax residency certificate and a filed first-year return, so the position is evidenced rather than assumed if questions come later.
Time the residence before the secondary or tender offer settles, with margin for the ROFR and lock-up delays above, and the gain lands in the 10% regime. Leave it to the week of closing, and you invite both a challenge from your former country and a residence tie-break under the applicable double tax treaty. Founders sequencing a full exit should read this alongside relocating before your RSUs vest, which handles the mirror-image timing problem for equity that is still vesting rather than being sold.
Common questions before booking:
Is this aggressive tax planning? No — the conservative route is genuinely moving, being provably resident before the deal, and paying a defined 10% on the profit. The risk lies in staging a departure while your life stays put.
Can I do it if the tender offer closes in a few weeks? Often not cleanly. A last-minute residence is the one thing to avoid; if the close is imminent, the honest answer may be to plan for the next liquidity event rather than force this one.
I am a US citizen — is this pointless? No, but it is different. Read the US caveat above: the US charge does not vanish, so the plan has to account for it head-on rather than assume relocation erases it.
What does Bulgaria charge me afterward? 10% flat on personal income and on the pre-IPO gain (on the profit), and a 15% combined framework for a company. VAT registration for a company becomes mandatory at EUR 51,130 of taxable turnover.
When This Is Not for You
An honest framework has to be able to say no. This move is the wrong call when:
- The deal closes before you can genuinely relocate. If the tender offer settles in weeks and you cannot establish real Bulgarian residence first, a paper move creates risk without the saving. Plan the next event, not this one.
- You are a US person and QSBS or CBT drives the outcome. If your gain is largely sheltered by Section 1202 in the US, or your US charge dominates, the Bulgarian saving may be smaller than it looks. Model it before you move.
- You cannot or will not truly leave. If family, work or other ties keep your centre of vital interests in your current country, a half-move is the outcome to avoid.
- You want a zero-tax fantasy. Private pre-IPO shares are taxed in Bulgaria at 10% — low, defined and defensible, not nil. If your plan depends on paying nothing anywhere, it is not a plan, it is an exposure.
Know in 48 Hours What Your Pre-IPO Sale Really Costs — and What Bulgaria Saves
Send us your holding, the expected offer or tender price, your cost or exercise basis, your rough close timing, your current country and whether you are a US person. We return a written read: your likely gain, how your home country would tax it, how a genuine Bulgarian residence at 10% on the profit compares, the honest US and QSBS caveats, and — if it fits — a realistic relocation and timing plan with numbers. Best fit: startup employees, early investors and angels with a secondary or tender offer on the horizon who want one clean, low-tax exit. Free, written, no obligation — no call needed unless you want one.
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Frequently Asked Questions
What is a pre-IPO secondary sale or tender offer?
How is this different from relocating before selling your whole company?
Does moving to Bulgaria make a pre-IPO gain tax-free?
If I am a US person, does relocating erase the US tax?
What does 409A valuation have to do with my sale?
Do ISOs, NSOs and RSUs change the timing?
What practical constraints affect the timing?
When does the Bulgarian residence have to be in place?
Disclaimer: This article provides general information on the taxation of pre-IPO secondary sales, company tender offers and Bulgarian tax residence as of July 2026. Startup-equity, US federal and home-country rules are detailed, fact-specific and change periodically; the US position (including citizenship-based taxation and any QSBS treatment) must be confirmed with US counsel, and home-country exit and trailing-residence rules with local counsel. Figures are indicative. Nothing here constitutes individual legal or tax advice. Last reviewed: July 16, 2026.