🇸🇪 Swedish Developer Cheat Sheet — personnummer, VAT, Bankgiro, public holidays, coordinates, all in one reference

swedish-dev-cheatsheet.md

🇸🇪 Swedish Developer Cheat Sheet

Everything you need to handle Swedish-specific data formats. Bookmark this.

Personnummer (Personal Identity Number)

Format: YYYYMMDD-XXXX (12 digits) or YYMMDD-XXXX (10 digits)

YYMMDD-XXXX
││││││ ││││
││││││ │││└─ Luhn checksum digit
││││││ ││└── Serial number (odd=male, even=female)
││││││ │└─── Serial number
││││││ └──── Serial number
││││└└────── Day (add 60 for coordination number)
│││└└─────── Month
│└└└──────── Year

Luhn algorithm: Multiply every other digit by 2, sum all digits, checksum = (10 - sum%10)%10

Coordination numbers: Day + 60 (e.g., person born on 15th → coordination number day = 75)

Century markers: - = 1900-1999, + = 2000-2099

Bankgiro

Format: NNN-NNNN or NNNNNNN (7-8 digits)

Validation: Mod-10 checksum on last digit

Multiply digits by 2,1,2,1,2,1,2 from right (skip checksum)
Sum all digits (products >9: subtract 9)
Valid if sum % 10 == 0

90-konto: Starts with 90 (charity accounts)

PlusGiro

Format: NNNNNN-N or NNNNNNN (7-8 digits)

Validation: Mod-10, same algorithm as Bankgiro

Organisationsnummer

Format: NNNNNN-NNNN (10 digits)

Same as personnummer but:

• Middle digit of serial number ≥ 2 (not 0 or 1)
• Month digits = 20+ for some types
• Third digit indicates legal form:
  • 0: Dead estates
  • 1: Municipalities
  • 2: State/landsting
  • 3: Foreign companies
  • 5: Aktiebolag (AB)
  • 7: Ekonomisk förening
  • 9: Handelsbolag/Kommanditbolag

Swedish VAT (Moms)

Rate	Applies to
25%	Most goods and services (default)
12%	Food, restaurants, hotels, camping
6%	Books, newspapers, public transport, culture

Add VAT: amount * (1 + rate)
Extract VAT: amount * rate / (1 + rate)
Remove VAT: amount / (1 + rate)

Arbetsgivaravgift (Employer Contributions)

Standard rate: 31.42% of gross salary

Lower rates (2026):

• 10.21% for persons born 2001-2006 (15-25 years)
• 10.21% for persons born 1960 or later (66+ years)

Public Holidays 2026 (Röda dagar)

Date	Name
Jan 1	Nyårsdagen
Jan 6	Trettondedag jul
Apr 3	Långfredagen
Apr 5	Påskdagen
Apr 6	Annandag påsk
May 1	Första maj
May 14	Kristi himmelsfärds dag
May 24	Pingstdagen
Jun 6	Nationaldagen
Jun 19	Midsommarafton
Jun 20	Midsommardagen
Nov 6	Alla helgons dag
Dec 24	Julafton
Dec 25	Juldagen
Dec 26	Annandag jul
Dec 31	Nyårsafton

Swedish Coordinates

System	Domain
RT90	Older Swedish grid
SWEREF99	Modern Swedish grid
WGS84	GPS (global)

RT90 → WGS84: Complex 7-parameter Helmert transformation
SWEREF99 ↔ WGS84: Minimal offset (centimeters)

Postal Codes

Format: NNN NN (5 digits)

• First two digits: geographic region
• 10-19: Stockholm
• 20-29: Skåne
• 30-49: Västra Götaland/Småland
• 50-69: Östergötland/Närke/Värmland
• 70-89: Dalarna/Gävleborg/Norrland
• 90-99: Västerbotten/Norrbotten

Phone Numbers

Prefix	Type
07X	Mobile (070=Telia, 073=Tele2, 076=Telenor, 079=Tre)
08	Stockholm area
031	Gothenburg
040	Malmö
020	Freephone
0900	Premium rate
112	Emergency

Currency Format

• Symbol: kr (after amount: 100 kr)
• Decimal separator: , (comma: 100,50 kr)
• Thousands separator: space (10 000 kr)
• ISO code: SEK

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Curated by Gracestack • Open source tools at github.com/cedendahlkim • MIT licensed — copy, fork, share freely