Differences Between U.S. and PCT Applications. Episode 34

Overview

In the last episode, I provided an overview of what PCT applications are and why you might want to file one.

In this episode, I’m going to go over some key differences between U.S. and PCT applications. Some of these differences are suggestions, while others are requirements.

For the most part, if your U.S. patent application was properly drafted, you won’t need to do much additional work to prepare it for a PCT application.

There are also different forms to fill out, which I will cover in the next episodes. In this episode, I will focus on differences in the application itself—including the description, figures, and claims. I will also be discussing electronic filing only, since that’s what you should be doing.

Formatting Differences

One major formatting difference is paper size.

A4 vs. U.S. Letter

• PCT applications should be prepared on A4-sized paper, which is the standard paper size used outside the U.S.

• The U.S. Patent Office will still accept U.S. letter-size paper if you file through the U.S. receiving office, but I recommend using A4 for consistency with other countries.

Margins

• General document margins:

• Minimum: 2 cm (top, right, bottom), 2.5 cm (left)

• Maximum: 4 cm (top, left), 3 cm (right, bottom)

• A simple 1-inch margin all around works well and is easy to remember.

• Figure margins:

• Minimum margins: 2.5 cm (top, left), 1.5 cm (right), 1 cm (bottom).

Line Spacing

• In U.S. applications, spacing can be up to 2.0.

• In PCT applications, it must be 1.5.

Reference Numbers in the Description and Claims

One major theoretical difference between U.S. and PCT applications is how reference numbers are used throughout the application.

Reference Numbers in the Abstract and Claims

• U.S. applications:

• Reference numbers only need to be included in the detailed description of the embodiments.

• They are not required in the abstract or claims.

• PCT applications:

• Reference numbers should be included whenever an element is mentioned—including the abstract and claims.

• Example:

• U.S. application: “The keychain has a ring.”

• PCT application: “The keychain (10) has a ring (12).”

• Reference numbers should be placed in parentheses and only for main features.

Although I’ve seen many PCT applications (including my own) that don’t include reference numbers in the abstract or claims, and the PCT office has never required corrections, some countries—like Europe—are more strict about this.

Including reference numbers from the start is a good practice to ensure compliance in countries that are picky about formatting.

Differences in Claim Drafting

Two-Part Claims in PCT Applications

The World Intellectual Property Organization (WIPO), which sets the rules for PCT applications, recommends drafting claims in a specific way.

This two-part claim format is commonly used in Europe but is not required for U.S. applications.

However, PCT rules do not require this format if the national laws of the country where you file don’t require it.

Example of a Two-Part Claim

Let’s say you invented a new keychain that includes:

• A ring

• A knife

• A pen

• A flashlight (the new feature)

In a U.S. application, the claim might read:

“I claim a keychain comprising a ring, a knife, a pen, and a flashlight.”

In a PCT application, the preferred format would be:

“I claim a keychain comprising a ring, a knife, and a pen, wherein the improvement further comprises a flashlight.”

This format clearly separates the existing features from the new inventive feature.

Although I have never received a PCT office notice requiring a two-part claim format, the European Patent Office (EPO) is more likely to enforce this rule.

Prior Art Disclosure Requirements

U.S. vs. PCT Applications

• U.S. applications:

• You must disclose any known prior art that may affect the patentability of your invention.

• This is done using the Information Disclosure Statement (IDS).

• PCT applications:

• You are not required to disclose or acknowledge any prior art that you know about.

Claim Limits and Fees

Claim Limits in the U.S.

• U.S. applications:

• 20 total claims (3 independent claims included).

• Additional claims require extra fees.

Claim Limits in PCT Applications

• PCT applications:

• No limit on the number of claims.

• Instead, the limit is on total pages:

• If your application exceeds 30 pages, you must pay an extra $15 per additional page.

Since there’s no claim limit, you might think, “Why not add hundreds of claims?”

While some applications do include hundreds of claims, it’s generally not a good strategy. If you need hundreds of claims to describe what makes your invention non-obvious, you may not have a strong invention to begin with.

Each dependent claim should introduce a new and non-obvious limitation over the independent claim—otherwise, they won’t help with patentability.

Multiple Inventions in One Application

U.S. vs. PCT Applications

Both U.S. and PCT applications have rules about multiple inventions in one application.

• If an application includes multiple inventions, the patent office may require that each invention be examined separately, and additional fees may apply.

• The standard for determining whether there are multiple inventions can vary.

This is a more technical issue, and I won’t go into detail in this episode, but it’s something to keep in mind when drafting your application.

Final Thoughts

Even if you don’t make any changes to your U.S. application, as long as it’s well-written, it will likely work fine as a PCT application with only minor revisions. I’m Adam Diament, and until next time, keep on inventing!