Free tool
ABN checker
Paste an Australian Business Number, or up to fifty, and see whether each one is built the way the ATO builds them and whether its check digits add up. Free, with no sign-up.
This checks how a number is built. Whether a business holds it, and whether it is registered for GST, onlyABN Lookup can say. Nothing you type is kept.
Questions people ask
What does the ABN checker check?
That the number is eleven digits and that its check digits add up the way the ATO builds them: subtract one from the first digit, weight the eleven digits, and the total divides by 89. A mistyped digit almost always breaks the check.
Does a valid result mean the business is registered?
No. A well-formed ABN can belong to a business that has been cancelled, or to nobody. Only ABN Lookup says whether an ABN is active and registered for GST.
Can I check several at once?
Yes. Paste up to fifty, one per line, and download the results as a CSV.
See it on your own kind of work
We set ReliTime up with a walkthrough rather than a sign-up form. We will take you through a working organisation, from a week of timesheets through approvals and work in progress to a tax invoice, answer your questions as we go, and set up yours.
Or write to hello@relitime.com.