Double taxation treaties

Countries write their tax laws without regard to one another, so it is entirely normal for two of them to claim comprehensive taxing rights over the same person at once — a family home in one state, a flat and a business in the other. Double taxation treaties exist to referee exactly that contest. Austria maintains treaties with around 90 jurisdictions, modelled as a rule on the OECD Model Convention, and where a treaty applies it overrides Austria's domestic taxing claims.

Two boundaries are worth fixing at the outset. First, a treaty does not decide whether you are an Austrian tax resident under domestic law — that turns solely on the domicile and habitual-abode tests explained on the page on when Austrian tax residence begins. The treaty operates one level up: it takes two competing domestic claims and confines each state to the taxing rights the treaty allocates to it. Second, a treaty does not lower Austrian rates on income Austria is entitled to tax. Treaty-resident Austrians pay the ordinary progressive rates of up to 55% on scale income and the flat 27.5% on most capital income; what the treaty changes is how foreign tax on the same income is neutralised. The domestic rules every treaty sits on top of are mapped on the overview of the Austrian tax system.

Austrian treaties relieve double taxation by one of two methods, and many treaties use both, income type by income type.

• Exemption — Austria leaves the source-taxed income out of the Austrian base altogether. Typically the exempt income still counts when setting the rate on the rest (the progression proviso), but the income itself bears only the source state's tax.
• Credit — Austria taxes the income in full and then credits the foreign tax against the Austrian liability, generally up to the amount of Austrian tax attributable to that income. The overall burden lands at the higher of the two levels.

The choice of method is anything but academic. Under the exemption method, income taxed lightly at source stays lightly taxed; under the credit method, Austria tops the burden up to its own level. The 2021 protocol to the treaty with the United Arab Emirates, in effect from 2023, illustrates the difference: it moved Austrian residents' Emirates income from exemption to credit, and with little or no Emirates tax to credit, such income became fully taxable in Austria overnight. For investment income the practical pattern is simpler: foreign withholding on dividends is capped by treaty, and the residual foreign tax is credited against the flat Austrian 27.5% described on the page on investment income and capital gains.

Around 90 treaties still leave a good part of the world uncovered. For income from a non-treaty jurisdiction, an ordinance issued by the Minister of Finance steps in: on the conditions it sets, Austria unilaterally credits the foreign tax or exempts the foreign income, so that double taxation is mitigated even where no treaty was ever negotiated. Relief under the ordinance is claimed in the Austrian tax return itself and taken into account in the assessment, not by separate application. A different route is needed where a treaty exists on paper but has been suspended — the Russian situation — because the ordinance presupposes that no treaty exists at all: relief there depends on a discretionary application to the Ministry of Finance under section 48(5) of the Federal Fiscal Code.

Unilateral relief is a backstop, not an equivalent. It follows Austrian conditions rather than negotiated ones, and it does nothing about the other country's taxation of Austrian-source income flowing the other way. Anyone whose wealth sits partly in non-treaty jurisdictions should map the exposure — and the paperwork — before residence begins rather than after.