A Bulgarian company's “NACE code” can refer to more than one record. The National Statistical Institute (NSI) assigns a principal economic activity for statistics, the Commercial Register may display an optional activity code, and the company's articles contain a written object of activity. A business pivot can affect one, two, or all three—but they do not change through one universal application.

That distinction is especially important after Bulgaria introduced KID-2025, its national version of NACE Rev. 2.1. The right process starts with the facts: what the company actually does, which activity generates its business, what its constitutional documents allow, and whether the new sector is regulated.

This guide provides general information as at 1 August 2026. It is not legal, accounting, tax, statistical, licensing, employment, or public-procurement advice for a particular business.

Changing a NACE Code at a Glance

KID-2025 and NACE Rev. 2.1

NACE is the EU's common classification of economic activities. Bulgaria's national implementation is the Classification of Economic Activities 2025 (KID-2025). It replaced KID-2008 for statistical use from 1 January 2025 and reflects the EU's NACE Rev. 2.1 structure. The NSI KID-2025 page provides the classification, explanatory materials, and access to its classification system. Eurostat's NACE overview explains the European transition.

Do not assume that an old code simply keeps the same digits. Some activities were split, merged, or moved. Start with the NSI correspondence tables, then read the new class description and its inclusions and exclusions. A mapping is a search aid, not a substitute for analysing the current operation. When one old class maps to several new classes, contracts, invoices, personnel, assets, and revenue streams should show which destination fits.

One Company, Three Different Questions

1. What is the statistical principal activity?

NSI's official KID-2025 methodology says that NSI determines an entity's principal activity once a year from its annual activity report. The Bulgarian operational indicator is net sales revenue. In the report's enterprise reference section, the business allocates relative shares of net sales between the activities it performs; NSI checks that information against the other submitted statements.

The wider NACE concept uses the activity contributing the greatest share of gross value added. Where that measurement is unavailable, suitable proxies are used. Bulgaria's published annual-report method uses net sales. Turnover and employment can still be valuable checks, but management should not choose a code solely because it sounds commercially attractive or employs the most staff.

Where more than two activities fall into more than two KID classes and none produces over 50% of net sales, NSI applies the top-down method. It selects the leading section, then division, group, and class in sequence. The result can differ from simply choosing the single class with the largest individual share. If the annual report contains no net sales, the published Bulgarian algorithm cannot determine a code on that basis, so the facts should be discussed with NSI rather than guessed.

2. What appears in the Commercial Register?

For an OOD or EOOD, the Registry Agency's A4 filing instructions distinguish field 6, “object of activity,” from field 6a, “principal activity according to KID.” Field 6 is mandatory; field 6a is expressly optional. A company that never populated field 6a does not ordinarily need an A4 solely to mirror NSI's annual classification.

If field 6a is already displayed and has become obsolete after a genuine change or the KID-2025 transition, updating it avoids contradictory public records. But the public entry does not displace NSI's statistical determination, and a registry official's acceptance is not a substantive confirmation that the selected activity matches the enterprise.

3. Does the object in the articles need amendment?

Article 115 of the Registry Agency's current Commerce Act requires an OOD's articles to contain its object of activity. If the existing wording already covers the new lawful business, changing only the statistical code does not necessarily require new articles. If the new operation falls outside that wording—or a sector law requires specific wording or prior approval—the members should amend the articles and update field 6.

For an OOD, amendment belongs to the general meeting and requires more than three quarters of the capital unless the articles demand more. A sole owner of an EOOD records a written decision. An object-only amendment is not among the Commerce Act decisions that automatically require simultaneous notarial certification of signatures and content, although the articles can impose a stricter form. The consolidated amended articles must be announced, and the amendment takes effect after registration.

A Practical Step-by-Step Process

1. Map the Actual Activities

Prepare a short operations schedule covering products and services, net sales by stream, personnel, assets, production method, customers, and expected changes. Separate principal, secondary, and ancillary activities. Ancillary internal functions such as bookkeeping or IT support for the same enterprise do not automatically become separate market activities.

2. Select and Test the KID-2025 Class

Use the official correspondence tables, classification headings, and Eurostat explanatory guidance. Read the “includes,” “also includes,” and “excludes” notes. For a mixed enterprise, perform the top-down calculation instead of selecting the largest class in isolation. Keep a dated calculation and the evidence used; it makes the next annual report and any authority or grant query easier to answer.

3. Audit Every Relevant Record

Compare the result with:

• the latest NSI annual activity report and statistical record
• Commercial Register fields 6 and 6a
• the articles or founding act
• NRA, employer-payroll, and self-insurance records that describe the activity
• sector registers, licences, permits, professional chambers, and facility approvals
• bank KYC, business insurance, grant, procurement, lease, and key contract profiles

There is no single general “NACE change” filing that silently updates all these systems. Give each record owner the information and evidence its own rules require.

4. Approve a Corporate Amendment Where Needed

If only optional field 6a is being aligned, confirm who is competent under the articles to approve the filing and record a clear decision. If the object must change, convene the general meeting with a specific agenda or prepare the sole owner's decision, adopt the new wording, and approve consolidated articles.

Typical OOD/EOOD documents include:

• member or sole-owner decision, with a voting record where applicable
• consolidated articles or founding act when their wording changes
• a disclosure copy with protected personal data redacted
• A4 application specifying the exact fields to be changed
• the applicant's statutory declarations and authority documents
• sector approval, licence, or permission where legislation makes it relevant
• fee evidence where payment is not confirmed automatically

An application changing “other circumstances” currently costs the euro equivalent of BGN 30 on paper—EUR 15.34—or BGN 15 electronically—EUR 7.67—under the Registry Agency's official fee tariff. The statutory decision point is immediately after three working days from filing, unless a special rule applies. Instructions, defects, or operational queues can extend completion, so do not promise a commercial counterparty a fixed registration date.

5. Align Reporting and Operations

Update accounting mappings so the next annual activity report allocates net sales consistently. If a self-insured person actually starts, interrupts, resumes, or ends a relevant labour activity, the NRA's self-insurance service sets a seven-day declaration deadline; merely editing a company code should not be confused with one of those factual events.

Employers should also ask payroll advisers whether the actual principal activity changes the work-accident and occupational-disease contribution rate. The statutory rate table is activity-based, so an inaccurate classification can create contribution risk. Update occupational-risk assessments when the work itself changes, not just the database label. Businesses adding employees can review the wider occupational health service requirements.

Licences, VAT, Tax, Procurement, and Banking

A NACE code is never permission to trade. Pharmacies, financial services, food operations, construction, transport, security, employment intermediation, tourism, and many other activities may require licences, registrations, qualified staff, approved premises, or continuing supervision. Obtain the sector approval before beginning regulated work. Adding impressive wording to the articles or a public code does not cure unlicensed activity.

A change of code does not by itself register or deregister the company for VAT. VAT consequences follow the actual supplies, turnover, place-of-supply rules, counterparties, and any exemption or special regime. The same is generally true of corporate income tax: the label does not select a new tax rate, but a changed business model can change deductibility, withholding, transfer-pricing, permanent-establishment, incentive, or sector-tax analysis. See our 2026 Bulgarian corporate tax guide for the wider framework.

Public procurement uses CPV codes to describe the subject of a contract; CPV and NACE are different classifications. A contracting authority or funding programme may nevertheless use economic-activity criteria for eligibility or support intensity. Read the exact tender, grant, and state-aid rules. Do not manufacture eligibility by filing a code unsupported by real historic activity.

After a material pivot, tell the bank and insurer before transaction patterns contradict the KYC or risk profile on file. Expect questions about products, markets, expected turnover, customer and supplier countries, premises, licences, and source of funds. The board should also review finance covenants, lease-use clauses, permits, customer contracts, and insurance exclusions for change notices or consent requirements.

Common Mistakes and Risk Controls

• Treating the correspondence table as automatic. A split or merge must be tested against the present business and explanatory notes.
• Choosing the code by preference. Principal activity is evidence-based; it is not an SEO, grant, or banking label.
• Using turnover mechanically in a complex group. Apply the NSI annual methodology and top-down hierarchy; document assumptions.
• Amending field 6a but not an outdated object. Check whether the articles and mandatory field 6 still cover the operation.
• Changing the articles when nothing requires it. A statistical update alone does not justify unnecessary corporate filings.
• Starting before licensing. Classification and registration do not replace sector permission.
• Ignoring downstream records. Payroll, NRA events, statistical reporting, grants, tenders, banks, insurers, and contracts follow their own rules.
• Overstating a universal transition duty. Field 6a is optional; assess the company's actual public entry and legal documents instead of filing by reflex.

A new company can avoid later inconsistencies by choosing accurate KID-2025 data, sufficiently clear objects, and required permissions from the start. Our Bulgarian company registration guide explains the incorporation sequence.

Lion Consult can review an activity map, distinguish the NSI classification from the company's registered objects, prepare an A4 filing and corporate documents, and coordinate licensing, tax, payroll, and KYC follow-up. Discuss your business activity change with our team.

The correct steps depend on the legal form, articles, revenue mix, reporting history, workforce, permits, and sector. Obtain tailored Bulgarian legal, accounting, tax, and regulatory advice before filing or starting a new activity.

Frequently Asked Questions

Is registering a NACE code mandatory in Bulgaria?

For an OOD or EOOD, Commercial Register field 6a is optional. The registered object of activity in field 6 remains mandatory, while NSI separately determines the statistical principal activity.

When did KID-2025 replace KID-2008?

KID-2025 became effective for Bulgarian statistical classification on 1 January 2025 and implements EU NACE Rev. 2.1.

How does NSI determine a company's principal activity?

NSI determines it annually from the annual activity report, principally using the relative net-sales shares reported for each activity. A top-down method applies to certain diversified enterprises.

Must the company amend its articles when its NACE code changes?

Only if the new business is outside the existing object of activity or sector legislation requires different wording or approval. A statistical-code change alone does not necessarily require amendment.

What does an OOD or EOOD Commercial Register change cost?

Under the current tariff, changing other registered circumstances costs EUR 15.34 on paper or EUR 7.67 electronically.

Does a NACE code authorize a regulated activity?

No. It does not replace a licence, registration, approved premises, professional qualification, or any other sector-specific permission.