This is for internationally mobile people who assume day-counting settles tax residence — and need to understand the test that often overrides it.
The 183-day rule is widely quoted because it is easy to count. It is not the only test of tax residence. Many countries can treat someone as resident because their permanent home, family, personal ties or economic life remains there, even when they spend fewer than 183 days in the country.
Why are 183 days not the whole story?
The 183-day rule is widely quoted because it is easy to count. It is not the only test of tax residence. Many countries can treat someone as resident because their permanent home, family, personal ties or economic life remains there, even when they spend fewer than 183 days in the country.
What is the centre of vital interests?
The phrase usually refers to the personal and economic connections that make one country the real centre of a person's life. It appears in domestic-residence rules and in treaty tie-breakers based on the OECD Model Tax Convention. It is a facts-and-evidence test, not a single document or a simple day count.
The usual order in a treaty tie-breaker
| Test | What the authority asks | Examples of evidence |
|---|---|---|
| Permanent home | Where is a dwelling available on a continuing basis? | Title, lease, utility bills, access and household contents. |
| Centre of vital interests | Where are personal and economic relationships closer? | Family location, business, work, bank activity, clubs, doctors and school records. |
| Habitual abode | Where does the person spend more regular time? | Day-count calendar, travel data and passport records. |
| Nationality | Which nationality is held? | Passport/citizenship records. |
| Mutual agreement | Can the two tax authorities resolve it? | Treaty procedure and professional submissions. |
What personal ties carry weight?
| Category | Examples |
|---|---|
| Family | Spouse or partner, dependent children, children's school, family home. |
| Home | Owned or leased home, availability, furnishings and ordinary use. |
| Daily life | Doctors, insurance, clubs, religious/community links and personal possessions. |
| Official records | Driving licence, voter records, local registration and correspondence address. |
What economic ties carry weight?
| Category | Examples |
|---|---|
| Work and management | Employment location, client meetings, board decisions and where the business is run. |
| Assets and banking | Main bank accounts, property, investments and borrowing. |
| Business operations | Office, staff, contracts, invoicing and key suppliers. |
| Tax and administration | Tax registrations, social security, insurance and local professional advisers. |
Why evidence matters
In a residence enquiry, authorities reconstruct the year from objective information: immigration records, mobile and payment data, card spending, home usage, company records, children's attendance and public registries. A claimed move must match the practical pattern of life. A residence certificate can be useful, but it is evidence, not an automatic answer to a competing country's claim.
A practical example
A founder spends 150 days in Country A and 160 days in Bulgaria. The founder retains a family home in Country A, their children attend school there, their spouse remains there and the founder regularly manages a business from that home. Bulgaria may still regard the founder as resident under its rules, but Country A may have a strong vital-interests claim. A treaty, if applicable, may need to resolve the dual-residence position.
How to make a move defensible
| Action | Why it helps |
|---|---|
| Establish an actual home in the new country | Supports permanent-home and lifestyle evidence. |
| Move family life where possible | Family and schooling are often highly persuasive. |
| Relocate management and work patterns | Align company decisions and activity with the chosen base. |
| Reduce old-country ties | Review home availability, work, memberships and registrations. |
| Keep contemporaneous records | Day log, travel records, leases, bills and decision records. |
| Obtain tailored advice before departure | Domestic rules and treaties vary significantly. |
How Bulgaria applies the idea
Bulgaria can consider a person tax resident if they spend more than 183 days in a 12-month period or if their centre of vital interests is in Bulgaria. For people with connections to more than one country, the domestic tests and any relevant treaty must be reviewed together.
Thinking Bulgaria?
Sovereignty Global helps internationally mobile individuals move their centre of vital interests to Bulgaria for real — home, family, management and the contemporaneous evidence that a residence enquiry actually tests. Explore Residency and Bulgaria, or Book a Consultation. Related: how to leave tax residency cleanly and the 183-day rule explained.
Sources
- OECD Model Tax Convention commentary.
- Bulgarian personal-income-tax rules.
- Domestic residence statutes and treaty guidance. The application is highly fact-specific, so take advice before asserting non-residence.