Are electronic signatures legally binding in Australia?

Electronic signatures have been recognised in Australia for over twenty-five years. The Electronic Transactions Act 1999 (Cth) — mirrored by state and territory equivalents — provides that a transaction is not invalid simply because it took place electronically.

Australian courts have repeatedly upheld electronically signed agreements, from exchanged emails to platform-based signing. The question in practice is rarely whether an e-signature can bind; it's whether you can prove who signed and that they meant to.

The three requirements

• Identification — the method identifies the signatory and their intention to sign.
• Reliability — the method is as reliable as appropriate for the purpose, or proven in fact to identify the signatory.
• Consent — the other party consents to the signature being given electronically.

The exceptions

A small set of documents still needs care: wills and codicils, some deeds depending on jurisdiction, certain court documents, and documents requiring a witness where the witnessing rules haven't been modernised. Deeds are the case where the answer changes at the State border — six of the eight jurisdictions require a witness for an individual's deed, and only some have express electronic-deed provisions. If a document is unusual, check the specific requirement first.

Day-to-day practice documents — engagement letters, tax return declarations, BAS authorisations, management letters, consents and directions — sign electronically without drama. The ATO client declaration is the worked example of section 10 operating in practice: the ATO accepts an emailed declaration with a typed name and no scanned signature, and says so in its own guidance — we have set out why, and where the different rule for the agent's lodgment signature comes from.

What makes an e-signature defensible

If a signature is ever disputed, you'll want evidence of the whole event, not just an image of a squiggle. A defensible platform records who was invited, to which email address, when they viewed the document, their express consent to sign electronically, when they signed, and from what device — and then seals the document so any later change is detectable.

Every Siggy envelope finishes as a tamper-evidently sealed PDF with a Certificate of Completion recording exactly that chain. The certificate travels with the document, so the evidence is in the file, not in a database you hope still exists in seven years.

Weighing one platform against another on that evidence trail? Siggy compared with DocuSign puts the two side by side on price and on what each records, with sources and check dates.