Nummerkoll: Swedish Numbers by zenith-ops

Nummerkoll checks Swedish identity and payment numbers right in your browser. Paste a number or select it on any page, right-click and choose "Check with Nummerkoll". You see instantly what it is and whether it is valid.

Built for bookkeepers, payroll and accounts-payable staff, small-business owners and anyone who types Swedish numbers into forms, invoices and banking portals.

WHAT IT CHECKS
• Personnummer and samordningsnummer (10 or 12 digits, with or without separator): checksum, date, age, normalised 12-digit form
• Organisationsnummer, including sole-trader numbers, plus the matching Swedish VAT number (SE…01)
• Bankgiro and plusgiro
• OCR / payment references (checksum and optional length digit)
• IBAN for 75+ countries (check digits and country length)
• Swedish bank account numbers (clearing + account): checksum per bank type, bank name, BIC and the IBAN built from it, using the 2026 clearing table
• Bank days: is a date a Swedish bank day? Which holiday? Next bank day? ISO week.
• Right-click any selected text to check it. Swedish and English interface.

PRIVACY FIRST
All checking happens locally in your browser. The extension has no analytics, no ads and no server of its own. Numbers you check are never stored or sent anywhere. The core checks make no network requests at all.

WHAT IT DOES NOT DO
Nummerkoll checks format and checksum only. A valid number is not proof that a person, company or account exists or is active. For that, use Bolagsverket, VIES, or your bank. Bank clearing data is based on public Bankinfrastruktur tables and may lag behind changes; the IBAN shown is a calculation, always verify important payments with the recipient.

Open-source validators, no tracking. Source: https://codeberg.org/moneyman-code/nummerkoll . Support: zenith-ops@mail.grokbot.com