Before you start

Personnummer and folkbokföring
A tax card (A-skattsedel) — automatic once registered
BankID, for the return and Skatteverket's e-services
For a Danish job: a Danish personal tax number and a forskudsopgørelse (preliminary income assessment) with SKAT
For expert relief on a Swedish salary, an application to Forskarskattenämnden within three months of starting work

Step-by-step

1
Establish which country taxes your employment income
Under the Öresund Agreement in the Nordic tax treaty, a cross-border commuter is taxed primarily in the country where the employer is based, provided they are physically present in that country for more than half of total working hours in any twelve-month period. Below that, days worked in Sweden become taxable in Sweden. Get the arithmetic right at the start of the year, not at the end.
OnlineWho: You and your employer
2
Register with SKAT and file in both countries
A Danish salary means a Danish personal tax number and a forskudsopgørelse — a preliminary income assessment that sets your Danish withholding. You will also still file a Swedish return, declaring the Danish income and claiming relief under the treaty. Filing in two countries is the normal condition here, not a sign of a mistake.
OnlineWho: You
3
Track your working days, seriously and in writing
The whole regime turns on where you were physically working on each day, and the burden of showing it falls on you. Keep a contemporaneous record from day one — a calendar export is enough — because reconstructing a year of home-working days after a query is miserable and rarely convincing.
Mobile appWho: You
4
For a Swedish job, check the municipality you are registering in
Municipal income tax is levied where you are registered as living, not where you work. Malmö is 32.42% for 2026 and Lund is identical at 32.42%, but Lomma next door is 30.72% — nearly two points lower, and inside the same commute. It is not a factor most newcomers know exists.
OnlineWho: You
5
Apply for expert tax relief within three months if you may qualify
For a Swedish employment, foreign key personnel can have 25% of salary exempted from Swedish income tax and employer contributions for up to seven years. The mechanical alternative test is recurring monthly income above 1.5 times the price base amount — SEK 88,801 a month for 2026. The application must reach Forskarskattenämnden within three months of your first working day, and there is no extension.
OnlineWho: You and your employerWithin 3 months of starting work
6
Confirm the pre-filled Swedish return each spring
Skatteverket sends a complete declaration in March covering salary, interest, dividends and property. If nothing needs changing you approve it with BankID. Filing closes in early May. Cross-border income is exactly the sort of thing the pre-filled return will not know about, so read it rather than approving on reflex.
Mobile appWho: YouMarch–May

Documents you’ll need

Personnummer
Employer's annual control statement (Sweden) or årsopgørelse (Denmark)
A contemporaneous record of where each working day was performed
Danish personal tax number and forskudsopgørelse, for a Danish job
Documentation for the expert relief application, including the employment contract

Things most newcomers don’t know

The Öresund Agreement was rewritten and the test changed on 1 January 2025 — most published advice is describing the old one.

The new agreement was signed on 10 June 2024 and applies from 1 January 2025. The old rule required at least half your working hours in the country of work within any three-month period; the new one requires more than half within any twelve-month period. A twelve-month window is far more forgiving of a busy quarter spent at home, and the new agreement also extends the rules to public-sector employees, who were previously outside them. Anything written before mid-2024 is describing a regime that no longer exists.

Source: Skattestyrelsen (SKAT) — private-sector Öresund commuters; the 2024 Öresund Agreement

Tax and social security are two different regimes with two different thresholds, and you must clear both.

For tax you need more than half your working hours physically in Denmark over twelve months. For social security, under EU Regulation 883/2004, working 25% or more of your time in Sweden puts your whole employment into the Swedish system — which for your Danish employer means Swedish employer obligations. They point in the same direction but they are not the same line, they are administered by different authorities, and clearing one tells you nothing about the other. A hybrid schedule has to satisfy both.

Source: Skattestyrelsen; Øresunddirekt / Försäkringskassan

Malmö's municipal tax rate has a two-point cheaper neighbour inside the same commute.

Malmö is 32.42% for 2026 and so is Lund. Lomma, immediately north of Malmö on the coast and on the same rail line, is 30.72% — closer to Stockholm's rate than to Malmö's. Your rate follows the address you are registered at, not the office you work in. Two colleagues on identical Malmö salaries take home noticeably different amounts because of which side of a municipal line they rented on.

Source: SCB — totala kommunala skattesatser 2026

Expert tax relief is worth a great deal and is lost on a three-month procedural deadline.

For a Swedish employment, 25% of salary exempt from income tax and from employer social contributions for up to seven years is a substantial sum. The alternative qualification is purely mechanical — recurring monthly income above 1.5 times the price base amount, SEK 88,801 for 2026 — so eligibility is usually obvious. What is not obvious is that the application must reach Forskarskattenämnden within three months of your first working day, and the deadline cannot be extended. Raise it during onboarding, not at your first return.

Source: Forskarskattenämnden / Skatteverket

Common mistakes to avoid

Relying on an article written before mid-2024, which describes the old three-month Öresund test rather than the twelve-month one.
Assuming that clearing the tax threshold also clears the social security threshold — they are separate rules with separate numbers.
Not keeping a contemporaneous record of where each working day was performed, and then having to reconstruct one.
Approving the pre-filled Swedish return on reflex in a year with Danish income it cannot see.
Missing the three-month deadline for expert tax relief on a Swedish employment.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.