ACN Generator

About Australian Company Numbers (ACN)

An ACN is the nine digit identifier the Australian Securities and Investments Commission issues to every company at registration. It appears on letterheads, invoices, contracts and email footers, and unlike a business name it never changes for the life of the company.

The ninth digit is a check digit: multiply the first eight by 8, 7, 6, 5, 4, 3, 2 and 1, take the total modulo 10, and subtract that from 10. Every number produced here satisfies that calculation, so it exercises real validation logic rather than slipping through a length check.

Leading zeros are the detail worth designing for. The oldest companies have numbers such as 000 000 019, and any system that stores an ACN as an integer will quietly turn that into 19. This generator produces zero-leading numbers at their natural rate, which makes it a fair test of whether your storage and display handle them.

To check a number instead, use the ACN validator, which also works out the ABN the company holds. For the eleven digit number, see the ABN generator.