TL;DR: Every Estonian OÜ must keep ongoing bookkeeping and file one annual report to the Business Register within six months of its financial year end (30 June for calendar-year companies), in XBRL format, even with zero activity. If you cross €40,000 in taxable turnover you become VAT-registered and owe a monthly KMD return. As of June 2026, expect roughly €30-80/month for a low-volume company through a bundled provider, €60-150/month for an independent Estonian accountant on a real business, and near-zero cash cost for disciplined DIY (verify with each provider). Recommendation: DIY only while dormant or pre-revenue, a bundled provider once you have a handful of monthly transactions, and an independent accountant the moment you register for VAT or hire.
What the law actually requires
Two obligations are non-negotiable and one is conditional.
First, ongoing bookkeeping. The Estonian Accounting Act requires every OÜ to record all business activity from day one - sales, purchases, bank movements, expenses - and keep source documents for seven years. There is no "we'll sort it at year end" exemption. The company board is personally responsible for this, not your provider.
Second, the annual report. Once per financial year, every company in the Commercial Register files a report to the Business Register: a balance sheet, an income statement, and notes. It is due within six months of the financial year end. The default financial year is the calendar year, so most companies file by 30 June. Since 2022 the register only accepts the report in XBRL format - the structured data format the e-Business Register portal generates for you - so PDF or Excel uploads are rejected. This applies even to a dormant company with no sales and no bank movements; you still file a "zero" report.
Third, and only if it applies to you: VAT. You must register for VAT once your taxable turnover crosses €40,000 in a calendar year, and you have three business days from crossing it to register with the Estonian Tax and Customs Board (EMTA). EMTA treats you as a taxable person from the moment supply hit the threshold, not from your registration date, so being late means the liability is backdated. Once registered, you file a monthly VAT return (KMD) by the 20th of the following month - every month, including quiet ones with no invoices. The standard VAT rate is 24% as of 2026 (it rose from 22% on 1 July 2025; verify the current rate at EMTA).
Note what is not on this list: there is no monthly corporate tax return on retained profit. Estonia taxes distributed profit only, at 22/78 on the gross distribution. Retained, reinvested profit is untaxed. We cover that mechanism in detail in Estonia corporate tax explained for non-residents. If you also run payroll - pay yourself a board-member salary or hire - you take on monthly TSD filings and social tax, which is where DIY usually breaks.
The three ways to keep the books
The realistic options are a bundled provider, an independent Estonian accountant, or doing it yourself. They are not interchangeable; each fits a different company stage.
Bundled providers (Xolo, 1Office, Companio, Unicount)
These are the formation companies that also sell accounting as a monthly subscription. You already meet them when you start an OÜ - the all-in cost breakdown covers their formation and address fees. Their accounting product is built for the e-resident solo operator: a clean dashboard, you upload or forward invoices, they categorise and file. The annual report is usually included in the subscription rather than billed separately.
The trade-off is that they are templated. They are excellent while your business is one person, a handful of invoices, and no payroll. They get expensive and rigid once you have real complexity - multiple currencies, inventory, employees, cross-border VAT (OSS), or anything that needs judgment. The cheapest tiers also often cap transaction counts, so a busy month can bump you up a bracket.
Independent Estonian accountants
A local bookkeeper or small accounting firm gives you judgment and flexibility a subscription does not. They handle messy reality - reclassifying a miscoded expense, structuring a salary-vs-dividend split sensibly, dealing with EMTA correspondence in Estonian, managing OSS VAT across EU sales. You communicate by email rather than a portal, which is slower but means an actual person knows your business.
The downside is sourcing one. The good ones often work in Estonian and find foreign clients through referral, so you have to look. Once you have VAT, payroll, or any operational complexity, this is the option that scales without surprises.
DIY
Legally you can do your own accounting; Estonia does not require you to appoint a professional. For a dormant holding company or a pre-revenue OÜ with two or three transactions a year, DIY is genuinely fine - you file the zero annual report through the e-Business Register yourself and pay nothing.
It stops being fine fast. The XBRL annual report is fiddly the first time, the VAT and TSD filing calendars are unforgiving, and a mistake is backdated to you personally as a board member. DIY works as a deliberate choice while there is nothing to get wrong, not as a cost-saving measure on an operating business.
Realistic cost ranges (as of June 2026, verify)
Pricing moves and every provider scopes "an invoice" differently, so treat these as ranges to verify against the provider, not quotes.
-
Dormant / holding (a few transactions a year): roughly €0 if you DIY the zero report, or €200-500 once a year if an accountant prepares it for you. Some bundled plans offer a low dormant tier.
-
Low volume (up to ~15-30 invoices/month, no VAT, no payroll): roughly €30-80/month with a bundled provider, or €60-120/month with an independent accountant. Annual report typically included.
-
Medium volume (VAT-registered, ~30-60 invoices/month, maybe one salary): roughly €80-150/month either way; this is where independents start earning their fee on VAT and payroll filing.
-
Higher volume (100+ invoices, multiple employees, OSS, inventory): €150-250+/month, almost always an independent firm or a custom-quoted bundled enterprise tier.
The single line item people forget is that the annual report is sometimes priced separately - €200-500 - if your monthly plan does not include it. Confirm whether yours does before you sign, because a "cheap" €30/month plan plus a €400 report is not cheap.
The other hidden cost is your own time. DIY is "free" only if you value the hours spent learning XBRL and tracking filing deadlines at zero, and only if you never trigger a backdated penalty. For most people past the dormant stage, a €40-80/month subscription buys back that risk cheaply.
What we'd actually recommend by stage
Match the option to where the company is, and switch when you cross a trigger rather than on a fixed schedule.
Pre-revenue or holding: DIY the bookkeeping and the zero annual report. There is nothing to get wrong, and paying a subscription to file blank returns is waste.
First real revenue, still solo, under the VAT threshold: a bundled provider. The dashboard discipline alone is worth €40-80/month, the annual report is handled, and you do not need a human accountant's judgment yet.
The moment you register for VAT, hire anyone, or start paying yourself a salary: move to an independent Estonian accountant. Monthly KMD and TSD filings plus salary-vs-dividend decisions are exactly the judgment a templated subscription does not give you, and the backdated-penalty risk on VAT makes a real person worth the slightly higher fee.
The trigger to switch is complexity, not revenue. A simple high-revenue OÜ (one product, EU-domestic, no staff) can stay on a bundled plan longer than a low-revenue one selling digital goods across five EU countries on OSS.
FAQ
Does an Estonian OÜ have to file an annual report even with no activity?
Yes. Every company in the Commercial Register files an annual report within six months of its financial year end, even with zero turnover, no employees, and no bank movements. A dormant company files a "zero" report. Missing it leads to fines on the company and board members personally, and eventually compulsory deletion from the register.
When is the Estonian annual report due in 2026?
Within six months of the financial year end. For companies on the default calendar financial year, that means 30 June 2026 for the 2025 financial year. It must be submitted in XBRL format through the e-Business Register; PDF and Excel are not accepted.
Do I need a monthly accountant if my OÜ is not VAT-registered?
Not legally - there is no monthly tax return for a non-VAT, no-payroll company, so the only hard deadline is the annual report. But you still must keep ongoing books and source documents for seven years. A low-cost bundled subscription is usually worth it once you have regular transactions; pure DIY only makes sense while activity is minimal.
When does an Estonian OÜ have to register for VAT?
When taxable turnover crosses €40,000 in a calendar year. You have three business days from crossing the threshold to register with EMTA, and liability is backdated to the moment supply hit €40,000 - not your registration date. After registering you file a monthly KMD by the 20th of the following month.
How much does Estonian OÜ accounting cost in 2026?
As of June 2026, roughly €30-80/month through a bundled provider for a low-volume company, €60-150/month with an independent accountant on an operating business, and near-zero for disciplined DIY on a dormant company. A standalone annual report can run €200-500 if not included in your plan. Verify current pricing directly with each provider.
Can I do my own bookkeeping as a non-resident e-resident?
Yes, Estonia does not require you to appoint a professional accountant. It is practical only while the company is dormant or pre-revenue. Once you have VAT, payroll, or steady transactions, the filing calendar and backdated-penalty risk make a provider or accountant the safer choice.
If you are weighing whether the whole structure still fits before you commit to a bookkeeping setup, the honest is an Estonian OÜ right for you checklist is a better starting point than picking an accountant first.