How Do You Prove You Invented Something First? A Plain Guide for Inventors

How do you prove you invented something first? In most of the world, being first to invent no longer decides who gets the patent. The US, Australia, Europe and most other countries give it to the first inventor to file a patent application. So the most useful thing you can do is file early and keep the invention confidential until you do. Dated records still matter, though. They help when someone copies an idea you showed them, when a collaborator or contractor claims your work, or when you need to show you were already using something before another person’s filing. This guide explains when “I had it first” still counts, and how to keep records that hold up.

Disclosure: I’m Inna Hall, an Australian lawyer and co-founder of TimeBinder, which is mentioned below. This is general information, not legal advice. Patent law differs between countries, so speak to a registered patent attorney before you file or disclose anything.

First to file changed what “first” means

For a long time the US was the odd one out. It awarded patents to whoever could show they invented first, which is why American inventors were told to keep signed and witnessed lab notebooks. That changed with the America Invents Act. For applications with an effective filing date on or after 16 March 2013, the USPTO applies first-inventor-to-file rules.

Australia already worked this way, and so do most countries. In practice, if two people independently come up with the same invention, the one who files first is usually in the stronger position, even if the other person had the idea months earlier. A notebook dated 2024 won’t normally beat someone else’s patent application filed in 2025 for an invention they arrived at on their own.

That is the uncomfortable part. The useful part is that “first” isn’t only about patents, and your records still do a lot of work.

When proving you were first still matters

Someone took your idea and filed it

First to file protects the first inventor to file, not someone who copied you. In the US, an inventor can bring a derivation proceeding against an earlier applicant who got the invention from them. According to the USPTO’s PTAB FAQ, the petitioner has to give substantial evidence that their inventor conceived the invention and communicated it to the other side, and the petition generally has to be filed within one year of the other party’s claim being published or granted. Dated records of what you had, and when you shared it, are exactly the kind of evidence that question turns on.

Disputes with collaborators, contractors and employers

Many invention disputes aren’t with strangers. They’re with a co-founder who left, a contractor who built the prototype, or a former employer who says the idea was developed on their time. Who contributed what, and when, often comes down to drafts, sketches, emails and test data. Your contracts set out who owns the result. Your records show what existed before the contract started and what came after.

You were already using it

Some countries, including the US and Australia, have a limited defence for someone who was already using an invention before another person’s patent was filed. The rules are narrow and vary, but they all depend on showing what you were doing and when.

Ideas you don’t plan to patent

Plenty of inventions are kept as trade secrets or never patented at all. If you share one under an NDA and it turns up in someone else’s product, you will want to show what you had before the meeting.

Grace periods are not a safety net

A common mistake is to publish, pitch or post about an invention first and file later. Some countries forgive this for a while:

• US: the inventor’s own disclosures made one year or less before the effective filing date generally aren’t counted as prior art against them.
• Australia: IP Australia says that if you’ve already gone public, you have 12 months to file your standard patent application.
• Many other countries, including those under the European Patent Convention, have no general grace period. Going public first can cost you protection there.

IP Australia’s advice is simple: until you’ve applied, keep it secret, use NDAs, and don’t post the invention online. A dated record helps you prove what happened. It doesn’t undo a disclosure.

What good invention records look like

The best records are boring, regular and made at the time. Aim for:

• Dated notebook entries describing the problem, your idea and each change, ideally signed and read by someone you trust who understands them.
• Sketches, CAD files and prototype photos, kept as original files rather than screenshots or re-exports.
• Test data and results, including the experiments that failed.
• Communications: emails and messages with collaborators, suppliers and investors, kept in full.
• Agreements: NDAs, contractor and employment terms, and invention assignment documents.
• A note of every disclosure: who saw what, when, and under what terms.

The weak spots in most records

Most inventors have records. The trouble is that many of them are easy to question:

• File dates on your computer can be changed in seconds, and they change when files are copied or synced.
• Emailing a file to yourself shows a date on a server you don’t control, and accounts get closed. We compare it in emailing yourself vs a blockchain timestamp.
• Posting a sealed envelope to yourself, the old “poor man’s patent”, is easy to challenge because envelopes can be resealed. See a better alternative to poor man’s copyright.
• Undated or rewritten notes invite the obvious question: when was this really written?

Where a blockchain timestamp fits

A blockchain timestamp gives a record an independent date that doesn’t depend on your computer, your email provider or your word. With TimeBinder, your browser calculates a SHA-256 fingerprint of each file. The fingerprint is recorded on the Bitcoin blockchain, and you get a Proof of Time Certificate. Your files are never uploaded, so the invention stays confidential. Later, anyone you choose can re-check a file against that record. If even one byte has changed, the fingerprint won’t match. You can see how fingerprints work with our free SHA-256 file hash checker.

Be clear about what this proves. A timestamp shows that a file existed no later than a certain time and hasn’t changed since. It doesn’t prove who created it, that the invention is new, or that you own it. It isn’t a patent, it doesn’t give you a priority date with any patent office, and because nothing is published it doesn’t make your invention prior art. It’s evidence of timing to sit alongside your notebook, your agreements and your patent filings. Our invention records page covers what inventors usually TimeBind.

An illustrative example (not a real case): an engineer sketches a new clamp design, builds a rough prototype and photographs it. Before pitching it to a manufacturer under an NDA, she TimeBinds the CAD file, the photos and the pitch deck together. Months later the manufacturer releases something similar and says they designed it in-house. She can’t use the timestamp to claim ownership on its own, but she can show exactly which files existed before the meeting, unchanged, which gives her lawyer something solid to work with.

A simple routine for inventors

When	What to do
Each working session	Write a dated notebook entry and save original files
Each milestone or prototype	TimeBind the drawings, photos and test results together
Before any meeting or pitch	Sign an NDA, then TimeBind exactly what you’ll show
Before you disclose publicly	Talk to a patent attorney and file first if you plan to patent
When someone joins or leaves	TimeBind the current state of the work and the agreements

AI can rewrite files. It can’t rewrite time. Give your invention records a date nobody can quietly change.

TimeBind Files Now →

This article is general information, not legal advice. Sources were checked on 26 October 2026.