Moving country for a job creates a set of tax questions that nobody mentions in the interview, and most of them have to be answered in a specific order. The expensive mistakes are almost always the same four: assuming residency changes on the day you land, forgetting the country you left still wants a return, not claiming an inbound regime inside its deadline, and discovering your new employer’s payroll has been using the wrong tax code for six months.
This is a practical checklist for the months either side of a move within Europe. It is general information, not advice on your own position — cross-border tax is the area where a couple of hours with an adviser most reliably pays for itself.
Tax residency: the question everything hangs on
Residency decides which country taxes your worldwide income. It is not the same as citizenship, and it is not decided by where your employer is or where you are paid. Each country sets its own test, and it is entirely possible to satisfy two at once.
The 183-day rule, and why it is not the whole rule
Most countries treat you as resident if you spend 183 days or more there in a tax year. That is where the rule’s usefulness ends. Three complications:
- The year is not always the calendar year. The UK tax year runs to 5 April, Ireland’s to 31 December, and some countries count any rolling twelve-month period.
- Day counting is technical. Whether a day of arrival, a day of departure or a day spent in transit counts varies, and the usual default — presence at midnight — is not universal.
- Other tests can make you resident on day one. Having a permanent home available to you, moving your family, or having your centre of vital interests in a country can establish residency well before day 183.
Tie-breakers when two countries both claim you
Double taxation treaties resolve this with a cascade, applied in order until one gives an answer: where you have a permanent home available; if both, where your personal and economic ties are closer (your centre of vital interests); then habitual abode; then nationality; and finally agreement between the two tax authorities. Most cases resolve at the first or second step.
The year you move is the difficult one
In your moving year you will usually have income in two countries and a residency status that changes part-way through. Several countries have split-year treatment, which divides the year into a resident and a non-resident part so that only the relevant income is taxed as resident income. Where it exists it is usually something you must claim, and it is often the single largest saving available in a moving year.
Where it does not exist, you may be treated as resident for the whole year, with your pre-move foreign income falling into the new country’s tax base and relief coming through a treaty credit instead. Either way you will very likely need to file in both countries for that year, even if you owe nothing in one of them.
How double taxation is actually avoided
Every EU and EEA country has a dense network of bilateral treaties, and they almost always prevent the same income being taxed twice. Two mechanisms do the work:
- Exemption. The country of residence does not tax the foreign income at all, though it may count it when setting the rate on your other income — “exemption with progression”.
- Credit. The country of residence taxes the income but subtracts the tax already paid abroad, capped at its own liability on that income. In practice you end up paying the higher of the two rates.
Relief is essentially never automatic. You claim it, on a return, with evidence of the foreign tax paid — so keep your foreign payslips and assessments.
Social security follows entirely separate rules. Within the EU, EEA and Switzerland you are generally insured in one country only, usually where you work. If you are posted abroad temporarily your employer can apply for an A1 certificate keeping you in the home system; without one, both countries can demand contributions, and unlike income tax there is no treaty credit to fix it afterwards.
Before you leave
- Tell the tax authority you are leaving. Most have a specific form or a departure section on the return. Skipping it is the most common cause of assessments chasing you years later.
- Check whether you still have a filing duty. Keeping property, a rental income, a business interest or significant savings in the old country usually means you keep filing there as a non-resident.
- Ask about exit taxes. Some countries deem unrealised gains on shares or business interests to be realised when you cease residency. Rarely relevant to a salaried move; very expensive when it is.
- Get your contribution record. A statement of the pension and social insurance you have accrued is far easier to obtain before you leave than after, and EU rules aggregate periods across member states.
- Keep the paperwork. Final payslips, the closing assessment, proof of dates of departure and arrival. You will need them for the split-year claim.
In your first months
- Register and get a tax number immediately. Until payroll has it, most systems apply an emergency or default code that over-deducts, sometimes heavily. It is refundable, but only after you fix it.
- Check your first two payslips against a calculator. A mismatch in the first month is normal; the same mismatch in the second means the code is wrong. Our country calculators are a quick way to sanity-check the deduction.
- Claim any inbound regime, in time. Spain, the Netherlands, Portugal, Ireland, Austria, Belgium and others tax qualifying new arrivals at a much reduced rate for a fixed period — but the deadlines are short and unforgiving, sometimes a few months from starting work. See the guide to special tax regimes. Missing the window usually means losing the whole benefit permanently.
- Register your family status. Marital status, dependants and a non-working spouse change the deduction materially in Germany, Belgium, Austria, Ireland and Portugal, and payroll will not know unless told.
- Sort healthcare cover. The gap between leaving one system and joining another is where people find themselves uninsured.
The expensive mistakes
- Assuming the move ends the old obligation. Interest and penalties accrue quietly on an unfiled return, and tax authorities inside the EU exchange information automatically.
- Missing an inbound regime deadline. The most costly single mistake on this list, often worth tens of thousands over the period the regime would have run.
- Working from the new country before officially starting. A few weeks of remote work from the destination can create a taxable presence, and occasionally a permanent establishment problem for your employer.
- Ignoring the A1 certificate on a posting. Double social security is not recoverable through a tax treaty.
- Comparing gross salaries. The whole reason this site exists — see the gross-to-net guide.