The 12‑Month Countdown You Cannot Ignore

— Why Missing Your Priority Deadline Means Losing Your Rights Forever

By Xing Zhiyong, China Patent Attorney | August 2026

I have had this conversation more times than I can count:

'I filed a U.S. provisional application last year. I'm planning to file in China — I'll get to it when I have time.'

'When did you file that provisional?'

'Fourteen months ago.'

'Then you've lost your priority right.'

'What do you mean? I haven't filed in China yet.'

'Exactly. And now you can't claim priority from your U.S. filing. The window is closed. Anyone can file before you now.'

This is not a rare mistake. It happens every week. And it is entirely preventable — but once the 12‑month window passes, the damage is permanent.

The Paris Convention Priority Rule: What You Must Know

The Paris Convention for the Protection of Industrial Property — which has over 170 member countries, including the United States, China, and most of Europe — establishes a fundamental rule:

You have 12 months from your first patent filing anywhere to claim priority in any other member country.

If you file a patent application in the United States on August 1, 2025, you have until August 1, 2026 to file a patent application in China — and claim priority from that U.S. filing.

If you file within that window, your China application will be treated as if it was filed on August 1, 2025 — the date of your U.S. filing.

If you file after that window, your priority claim is invalid. Your China application will be treated as filed on the date you actually file in China — and anyone who filed in the meantime will have priority over you.

The 12‑month window is strict. It cannot be extended. There are no exceptions.

What Priority Means — and What Happens When You Lose It

If You Claim Priority Within 12 Months:

• Your China application is treated as filed on the date of your first filing.
  
• Anyone who filed a similar application in China after your U.S. filing date is behind you.
  
• You have priority over them.
  

If You Miss the 12‑Month Window:

• Your China application is treated as filed on the date you actually file in China.
  
• Anyone who filed in China between your U.S. filing date and your actual China filing date is ahead of you.
  
• You have lost priority over them.
  

This is not a minor procedural issue. This can be the difference between owning the rights and being blocked by someone else.

A Story That Happens Every Month

A German inventor developed a new type of medical clamp. It was innovative, compact, and had clear clinical applications. He filed a German patent application on January 15, 2025. He was proud of his invention and knew it had commercial potential.

Over the next year, he was busy. There were trade shows. Discussions with manufacturers. A prototype update. A website launch. Everything was moving fast.

He looked up from his calendar in February 2026 and realized: he had never filed in China. It was now past January 15, 2026. His priority window had expired.

He filed a China patent application anyway. But the examiner found a similar application filed in China by a competitor — filed on September 20, 2025.

The competitor had seen the German inventor's product at a trade show, wrote a description, and filed in China before the German inventor ever did.

The German inventor's application was rejected. He had lost priority. The competitor now owned the Chinese rights.

The cost to the German inventor: the entire Chinese market, and a competitor who could now block him from using Chinese manufacturers for his global sales.

All because he missed a 12‑month deadline.

Why Inventors Miss This Window

I see four common reasons why inventors miss the priority deadline:

Reason 1: 'I didn't know there was a deadline.'

This is the most common — and the most avoidable. Some inventors assume that filing a 'worldwide' PCT application covers them everywhere. It doesn't. Some assume they can file whenever they want. They can't.

Reason 2: 'I was too busy.'

Business moves fast. Product development, fundraising, manufacturing discussions — it's easy to lose track of a 12‑month deadline. But the patent office doesn't care about your busy schedule. The window is fixed.

Reason 3: 'I thought I could file a PCT application first, and then enter China later.'

You can. But the PCT priority window is also 12 months from your first filing. If you file a PCT application within 12 months, and then enter China within 30 months, you can claim priority. But the key is this: you must file the PCT application (or a direct China application) within those first 12 months. You cannot use the 30‑month window to extend the priority claim deadline. The PCT gives you more time to decide where to file — not more time to claim priority.

Reason 4: 'I didn't think I needed China protection.'

Sometimes inventors change their minds. They decide later that China matters — but by then, the priority window is closed. The rule is simple: if you think you might need China protection, file within 12 months. You can always abandon the application later. You cannot go back in time.

The Cost of Missing the Priority Deadline

This is not a hypothetical risk. It is the most common reason foreign inventors lose their rights in China.

What the Smart Inventors Do

The smartest inventors I work with follow a simple rule:

'File in China within 12 months of your first filing — even if you're not sure you need it.'

Here's their logic:

• A China patent filing costs $2,500–$4,500.
  
• If you decide later you don't need it, you can abandon it — and you've spent $2,500 as a 'lottery ticket' for the world's largest market.
  
• If you decide later you do need it, and you already filed, you have preserved your rights. You haven't lost anything.
  

Filing early gives you optionality. Waiting gives you nothing.

Your Priority Deadline Checklist

'But I Filed a Provisional Application — Does That Count?'

Yes. A provisional patent application in the United States counts as a first filing for priority purposes. The 12‑month window starts from your provisional filing date.

But here is the critical part:

If you do not file your China patent application — or a PCT application — within 12 months of your provisional filing date, your priority claim expires.

Your provisional application itself expires 12 months after filing. It cannot be used to claim priority after that date.

So if you file a provisional on June 1, 2025, you have until June 1, 2026 to file in China and claim priority. There is no extension.

What You Can Still Do If You Missed the Window

If you have already missed the 12‑month window, you have limited options:

Option 1: File in China anyway — without claiming priority.
This gives you a new filing date. But you may already be behind someone else.

Option 2: Check whether anyone else has filed.
If no one has filed yet, you may still be able to get a patent. But you are now racing against time — and anyone else.

Option 3: Use the PCT 30‑month window if you filed a PCT application.
If you filed a PCT application within 12 months of your first filing, you still have 30 months from the first filing to enter China. But the priority claim is already preserved — you just need to complete the national phase entry.

Option 4: Ask whether any grace period applies.
China does not have a general grace period for foreign inventors. There are limited exceptions (e.g., disclosure at a government‑recognized international exhibition), but they are narrow and rarely apply. Do not assume this will save you.

The Bottom Line

The 12‑month priority window is the most important deadline in international patent strategy.

• It cannot be extended.
  
• It is the same for all member countries.
  
• If you miss it, you lose your rights.
  

Mark it on your calendar. Set reminders. File early, even if you're not sure.

You cannot go back in time. But you can act today.

We Can Help

Chengdu Yuhang Patent Agency (General Partnership) is a CNIPA-licensed firm (Registration No. 51283) that specializes in helping foreign individuals and small businesses file patents in China.

We help you protect your priority rights — by filing on time, every time.

• Priority date tracking — we never miss your 12‑month window
  
• Fast filing — from disclosure to filing in 2–4 weeks
  
• Fixed‑fee packages — no hidden costs
  
• PCT national phase expertise — we handle the complex entry process
  

'The 12‑month window is your only chance to preserve your priority rights. Don't miss it.'

Contact us for a free 15‑minute case review.

???? +86 28 84400310
???? rongduyuanli@163.com
???? CNIPA Registration No.: 51283

This article is for informational purposes only and does not constitute legal advice. Patent laws vary by jurisdiction. Consult a qualified professional for advice specific to your situation.