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Australia TIN validator
Check whether a Australia TFN / ABN follows the expected structure before you save it, send it to an API, or include it in a tax workflow.
Private by design
Your data stays in your browser
None of the TIN data you enter is ever saved to our servers — validation runs entirely on your device.
Validation Workspace
Validate TFN / ABN
Enterprise checks for Australia tax identification numbers.
Instant one-by-one format validation
How Australia tax IDs are formatted
In Australia, the tax identifier is commonly known as Tax File Number / Australian Business Number (TFN / ABN). The expected format is TFN: 8-9 digits, ABN: 11 digits with mod-89 checksum. Teams usually need a Australia TFN / ABN check around tax lodgment, employment, banking, or before a record moves into billing, onboarding, or compliance review.
Valid examples
123 456 78251 824 753 556
Invalid examples
- 123 456 789 (Invalid checksum)
- 5 182 475 355 (Too short)
What this validator checks
Format and length
Confirms the number follows the expected Australia pattern: TFN: 8-9 digits, ABN: 11 digits with mod-89 checksum.
Checksum logic
Runs the checksum rule used by Australia when the public format includes one, helping catch typos that still look correctly formatted.
Useful examples
Shows valid and invalid-looking samples so you can compare spacing, separators, letters, and digit counts before submitting real data.
When people usually check this number
- Tax lodgment
- Employment
- Banking
- Superannuation
A format match does not prove that a Australia tax ID belongs to a specific person or business. Use the result as a first-pass data quality check, then confirm sensitive cases with official records.
Official source: Australian Taxation Office
Last reviewed: May 23, 2026. We update country guidance when public format rules change.
How to check a Australia TFN / ABN
Use this check before a record reaches billing, tax reporting, or manual review.
Enter the TFN / ABN
Paste or type the Australia tax identifier exactly as it appears in your source record. Spaces and separators are fine when they are part of the expected format.
Review the format result
Check whether the number matches the known Australia structure, including length, separators, letters, and checksum rules where public guidance includes them.
Confirm important records
For onboarding, tax reporting, or compliance work, treat the result as a data-quality signal and confirm high-risk records with Australian Taxation Office or your internal process.
Frequently asked questions
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