Swedish SRU File Generation

This skill contains the complete technical specification for generating valid SRU files accepted by Skatteverket's filöverföringstjänst. The canonical source is Skatteverket's "Teknisk information om filöverföring" page (replaced brochure SKV 269 from Jan 1 2024).

Before writing any SRU generation code, read references/sru-codes.md for the complete field code tables and BAS-to-SRU mapping.

Architecture: Two files, always

Every SRU submission consists of exactly two files:

File	Content	Max size
INFO.SRU	Submitter metadata (who is filing)	—
BLANKETTER.SRU	All blankett blocks with tax data	5 MB

File names are case-insensitive but must not be renamed (browsers appending (1) cause rejection).

INFO.SRU structure

Posts must appear in this exact order. Omit optional posts entirely if not used.

#DATABESKRIVNING_START
#PRODUKT SRU
#MEDIAID <free-form ID>
#SKAPAD <YYYYMMDD> <HHMMSS>
#PROGRAM <program name and version>
#FILNAMN BLANKETTER.SRU
#DATABESKRIVNING_SLUT
#MEDIELEV_START
#ORGNR <12-digit org number>
#NAMN <submitter name, max 250 chars>
#ADRESS <postal address>
#POSTNR <5-digit postal code>
#POSTORT <city>
#AVDELNING <department>
#KONTAKT <contact person>
#EMAIL <email>
#TELEFON <max 15 chars>
#FAX <max 15 chars>
#MEDIELEV_SLUT

Mandatory posts: #PRODUKT, #FILNAMN, #ORGNR, #NAMN, #POSTNR, #POSTORT.

The #PRODUKT value is always SRU (post-2013). There is no #PERIOD post — period is encoded in each blankett type string.

BLANKETTER.SRU structure

Contains one or more blankett blocks, terminated by #FIL_SLUT:

#BLANKETT <BlankettTyp>
#IDENTITET <OrgNr> <YYYYMMDD> <HHMMSS>
#NAMN <taxpayer name>
#UPPGIFT <FältKod> <FältVärde>
... (repeat #UPPGIFT for each field)
#BLANKETTSLUT
... (repeat #BLANKETT blocks for each form section)
#FIL_SLUT

INK2 requires three blankett blocks

An aktiebolag filing INK2 must include three separate blocks in this file:

Block	BlankettTyp example	Content
INK2	INK2-2024P4	Huvudblankett (page 1) — summary fields
INK2R	INK2R-2024P4	Räkenskapsschema (pages 2-3) — balance sheet + income statement
INK2S	INK2S-2024P4	Skattemässiga justeringar (page 4) — tax adjustments

Period suffix rules

The suffix after the hyphen encodes when the fiscal year ENDS:

Suffix	Fiscal year ends in months
P1	January–April
P2	May–August
P3	Special cases
P4	September–December (calendar-year companies)

The year in the type string is the INCOME YEAR (inkomstår), not the filing year. A company with fiscal year 2024-01-01 to 2024-12-31 uses period 2024P4.

Each block is independent

Every blankett block carries its own #IDENTITET line. The DatFramst timestamp determines version precedence — later timestamps replace earlier submissions for the same org number and blankett type.

Encoding and formatting rules

Encoding: ISO 8859-1 (Latin-1)

This is the single most common source of validation failure in programmatic SRU generation. Never use UTF-8. Swedish characters (å, ä, ö) will corrupt.

When writing files in code:

• Python: open(path, 'w', encoding='iso-8859-1')
• Node.js: Use iconv-lite to encode to iso-8859-1 before writing
• Java: new OutputStreamWriter(fos, StandardCharsets.ISO_8859_1)

Line endings

All three conventions accepted: \r\n (Windows), \r (classic Mac), \n (Unix).

Amount formatting

• Integers in hela kronor (whole SEK). No öre, no decimals.
• Positive: no sign, no leading zeros. Example: 1000
• Negative: - prefix. Example: -1000
• No thousands separators. 7 135 with a space WILL fail.
• Truncation rule per SFL 22 kap. 1 §: öre are DROPPED (truncated), not rounded.
• Small rounding differences from öre truncation across multiple posts are accepted by Skatteverket.

Org number format

Always 12 digits, format SSÅÅMMDDNNNK, no hyphens.

• Juridiska personer (companies): century prefix 16
• Example: org nr 556000-0100 becomes 165560000100

Checkbox fields

Value: uppercase X. If unchecked, omit the entire #UPPGIFT line — never send empty values.

The # character

Reserved for post names. Forbidden in all string data values.

Zero-value handling

Do not emit #UPPGIFT lines for fields with zero value. Omit them entirely. Including zero-value fields is a common source of validation warnings and in some cases errors.

Complete example: calendar-year 2024 AB

INFO.SRU

#DATABESKRIVNING_START
#PRODUKT SRU
#SKAPAD 20250401 100000
#PROGRAM Luka 1.0
#FILNAMN BLANKETTER.SRU
#DATABESKRIVNING_SLUT
#MEDIELEV_START
#ORGNR 165590001234
#NAMN Exempelbolaget AB
#POSTNR 11122
#POSTORT Stockholm
#KONTAKT Anna Andersson
#EMAIL anna@exempel.se
#MEDIELEV_SLUT

BLANKETTER.SRU

#BLANKETT INK2-2024P4
#IDENTITET 165590001234 20250401 100000
#NAMN Exempelbolaget AB
#UPPGIFT 7011 20240101
#UPPGIFT 7012 20241231
#UPPGIFT 7113 90000
#BLANKETTSLUT
#BLANKETT INK2R-2024P4
#IDENTITET 165590001234 20250401 100001
#NAMN Exempelbolaget AB
#UPPGIFT 7011 20240101
#UPPGIFT 7012 20241231
#UPPGIFT 7201 100000
#UPPGIFT 7281 50000
#UPPGIFT 7301 50000
#UPPGIFT 7302 25000
#UPPGIFT 7410 500000
#UPPGIFT 7513 -200000
#UPPGIFT 7514 -150000
#UPPGIFT 7450 75000
#BLANKETTSLUT
#BLANKETT INK2S-2024P4
#IDENTITET 165590001234 20250401 100002
#NAMN Exempelbolaget AB
#UPPGIFT 7011 20240101
#UPPGIFT 7012 20241231
#UPPGIFT 7650 75000
#UPPGIFT 7651 15000
#UPPGIFT 8020 90000
#BLANKETTSLUT
#FIL_SLUT

Validation errors

Skatteverket validates on upload and returns a mottagningskvittens.

Level 1 (entire submission rejected)

• Structural errors in INFO.SRU
• Posts in wrong order in any blankett block
• More than 100 level 2 errors total
• Missing #FIL_SLUT
• Unknown post types
• #FILNAMN referencing nonexistent file

Level 2 (individual blankett block rejected, others accepted)

• Invalid org number
• Field code not valid for the blankett type
• Value violates field rules (wrong data type, out of range)
• Missing mandatory timestamp
• Invalid blankett type string

Most frequent real-world failures

1. Renamed files — browsers adding (1) suffix
2. Wrong period — using 2025P4 when income year is 2024
3. Amounts with decimals or spaces — 7135.50 or 7 135
4. UTF-8 encoding instead of ISO 8859-1
5. Including #UPPGIFT for zero/empty values
6. Duplicate field codes in same blankett block
7. 10-digit or hyphenated org number instead of 12-digit
8. Non-existent SRU codes — mapping BAS accounts to wrong field codes

BAS-to-SRU mapping: critical rules

The official mapping is maintained by BAS-kontogruppen + Skatteverket at bas.se/kontoplaner/sru/.

The #1 mapping error: BAS accounts 5000-6999 (övriga externa kostnader) must ALL aggregate into a single SRU code: 7513. Do NOT create individual SRU codes per BAS account in this range.

INK2S codes are NOT auto-derived from BAS accounts. They represent tax adjustments requiring manual calculation. The bookkeeping result flows from INK2R into INK2S field 7650/7750, then tax adjustments are applied to arrive at 8020/8021 (överskott/underskott).

For the complete SRU code tables and BAS mapping, read references/sru-codes.md.

Data type reference

Type	Format	Range
Numeriskt_A	Integer	-999,999,999,999 to 999,999,999,999
Numeriskt_B	Integer	0 to 999,999,999,999
Datum_A	YYYYMMDD	Valid calendar date
Tid_A	HHMMSS	00:00:00 to 23:59:59
Decimal_2	x.xx	-9,999,999,999.99 to 9,999,999,999.99
Andel_4	x.xxxx	0.0000 to 100.0000
STR_250	String	Max 250 chars, no #

Key external references

• Skatteverket tech spec: skatteverket.se/foretag/inkomstdeklaration/forredovisningsbyraer/tekniskinformationomfiloverforing
• BAS SRU mappings: bas.se/kontoplaner/sru/
• Annual field code ZIP packages: download from Skatteverket tech spec page (Excel files per period)
• Validation service: www1.skatteverket.se/fv/fv_web/start.do
• Open-source reference implementations: github.com/thpe/pysru-accounting, github.com/aidium/SRU-Maker