Where does C21 Patents, LLC rank among US patent assignees?

According to USPTO PatentsView (2015–2025 granted utility patents), C21 Patents, LLC ranks #20,879 of 49,997 assignees by granted-patent volume, the same sort as the companies listing and top-holders ranking. See /methodology/#corpus-placement.

How many patents does C21 Patents, LLC hold?

C21 Patents, LLC holds 13 US utility patents granted between 2015 and 2018, spanning 10 technology areas.

What is C21 Patents, LLC's Innovation Score?

C21 Patents, LLC has an Innovation Score of 30.4 out of 100 (34th percentile of the corpus). This composite metric weighs portfolio volume (40%), grant velocity (20%), technology breadth (25%), and claim depth (15%).

What technology areas does C21 Patents, LLC focus on?

C21 Patents, LLC's top technology area is H04M (Telephonic Communication) with 9 patents, ranking #491 of 2,488 assignees active in that subclass. Grants appear in 10 CPC subclasses total.

Is C21 Patents, LLC's patent grant rate increasing or decreasing?

C21 Patents, LLC's recent grant velocity is -100% compared to the prior five-year period (grant years, not application filing dates). Grant activity has slowed relative to earlier years.

What does claim depth mean for C21 Patents, LLC's patents?

C21 Patents, LLC's patents average 16.9 claims each. This is an aggregate descriptive count from the grant record; it does not establish claim scope, legal strength, enforceability, or design-around risk.

How is the C21 Patents, LLC patent data sourced?

All patent data comes from USPTO PatentsView, a public research dataset maintained by the United States Patent and Trademark Office covering US granted utility patents from 2015 to 2025.

USPTO 2015–2025 USPTO PatentsView US Corporation

C21 Patents, LLC

USPTO PatentsView assignee record - 13 granted patents across 10 technology areas, recorded in grant years 2015–2018. Grant-trend analysis is cross-referenced to USPTO Patent Public Search; it does not measure application filings, current R&D, or legal strength. Primary class: H04M (Telephonic Communication).

Compiled by PlainPatent · May 15, 2026

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Explore the portfolio See the ranking

The verdict

According to USPTO PatentsView, C21 ranks #20,879 of 49,997 tracked US assignees by granted-patent volume, with 13 patents across 10 technology areas.

#20,879
of 49,997 US assignees by volume: 34th percentile
by Innovation Score (30.4/100): 16.9
avg claims per patent: -100%
grant velocity, last 5 yrs

USPTO PatentsView assignee plate

Corpus R20879 · US Corporation #20,879 · 13 grants

GRANTS-MICRO · MID-PACK · PHOTO-FINISH · CPC-FOCUS · INNOV-THIN · CLAIMS-RICH · TYPE-USCORP · VEL-DROP · BOOK-FULL

GRANTS-MICRO 13 grants
MID-PACK #20,879/49,997
PHOTO-FINISH Burrow
CPC-FOCUS H04M · 10 areas
INNOV-THIN 30.4/100
CLAIMS-RICH 16.9 claims/avg
TYPE-USCORP US Corporation
VEL-DROP -100% vel
BOOK-FULL 10/10 fields

Nearest grant-volume peer: Burrow, Inc. (±0 grants)

Instrument codes from this assignee’s USPTO PatentsView grant sheet: volume band, corpus rank, photo-finish peer, lead CPC, Innovation Score, claim depth, assignee type, velocity, and book completeness. Not a USPTO rating of patent strength.

How C21’s 30.4 Innovation Score adds up

The same four weighted components behind every Innovation Score on PlainPatent: portfolio volume, grant velocity, technology breadth, and claim depth.

Volume 9.1 pts (30%) Velocity 0.0 pts (0%) Breadth 11.2 pts (37%) Claim depth 10.1 pts (33%)

Qualcomm Incorporated · highest

85
C21 Patents · this assignee

30
3D Lighting… · lowest

7

What this shows C21's Innovation Score is 30.4/100 (34th percentile of the PatentsView-derived corpus). The chart places that score against the nearest Innovation Score peers plus corpus poles, not a reprint of the volume ranking.

Does more volume mean deeper claims for C21?

Each dot is one of C21’s 8 nearest volume peers (same corpus rank neighbourhood as the chart above), placed by total granted patents (horizontal) against average claims per patent (vertical). C21’s own 16.9 claims/patent is at or below the 17.5 median for these volume peers. Volume here does not track with deeper claims; several lower-volume peers claim more thoroughly per patent.

C21 vs its 8 nearest volume peers: granted patents vs average claims per patent. Source: USPTO PatentsView.

Where C21's grants concentrate

C21 Patents, LLC is a focused PatentsView assignee: 10 CPC subclasses with 69.2% of grants classified under H04M (Telephonic Communication). Peak complete grant year is 2017 (4 grants) versus a trough of 2 in 2016. By volume, C21 sits between Burrow, Inc. and Calsonic Kansei North America, Inc..

Burrow

13
C&C Power

13
C E R M E X Const…

13
C I V -Consorzio…

13
Caes Systems

13
California Norths…

13
Calin Technology

13
Calsonic Kansei N…

13
C21 Patents ◀

13

What this shows C21 holds 13 patents at rank #20,881, shown against the 8 assignees closest to it in grant volume rather than the industry's largest filers.

Companies ranked near C21

By rank, the assignees closest to #20,881 in granted patent volume.

Leaders in H04M (Telephonic Communication)

Other assignees with the most granted patents in C21's primary technology class.

C21's Innovation Score vs. every tracked assignee

Composite of portfolio volume, grant velocity, technology breadth, and claim depth (0–100)

30 34th percentile higher than 34% of 49,997 US assignees

Each bar is a band; taller bars hold more US assignees. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source USPTO PatentsView, PlainPatent Innovation Score · 2015–2025

USPTO utility patent grants by year · 2015–2018

Grants by year

Teal-shaded recent years (2020–present) versus the 2015–2019 baseline. Full figures in the table below.

View data table

C21 Patents, LLC patent grants by year, 2015–2025
Year	Patents Granted	Share of Period
2015	3	23.1%
2016	2	15.4%
2017	4	30.8%
2018	4	30.8%

Which technologies does C21 Patents, LLC patent most?

H04M - Telephonic Communication 9

G10L - Speech Analysis Techniques OR Speech SYNTHESIS; Speech RECOGNITION; Speech OR Voice Processing TECHNIQUES; Speech OR Audio Coding OR Decoding 4

H04W - Wireless Communication Networks 3

G09B - Educational OR Demonstration APPLIANCES; Appliances FOR Teaching, OR Communicating With, THE Blind, Deaf OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; Diagrams 2

H04N - Pictorial Communication, e.g. Television 2

G06F - Electric Digital Data Processing 2

H04L - Transmission OF Digital Information, e.g. Telegraphic Communication 2

H04B - Transmission 1

Y02D - Climate Change Mitigation Technologies IN Information AND Communication Technologies [ICT], I.E. Information AND Communication Technologies Aiming AT THE Reduction OF Their OWN Energy USE 1

Y02B - Climate Change Mitigation Technologies Related TO Buildings, e.g. Housing, House Appliances OR Related End-user Applications 1

Top 10 of 10 technology areas

More on this record

Data Source

USPTO PatentsView, US granted patents 2015–2025

View all rankings → How is Innovation Score calculated?

What to do with this data

C21 Patents, LLC's patent record in context - here's where to go next.

C21 Patents, LLC's lead technology class is H04M (Telephonic Communication), 69.2% of its portfolio - see every assignee active in that class. Explore H04M
Ranked #20,879 of 49,997 tracked assignees by patent volume - see the full leaderboard. See the ranking
Compare C21 Patents, LLC against Burrow, Inc., an assignee filing at a similar volume. Compare portfolios
Innovation Score of 30.4/100 blends volume, velocity, technology breadth, and claim depth. How it's calculated

Figures reflect USPTO PatentsView grant data through May 2026; pending applications not yet granted are not counted.

Data sourced from USPTO PatentsView - official U.S. government patent data. See our methodology for computation details. Retrieved and formatted by PlainPatent

Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from the USPTO PatentsView database. Consult a qualified professional before making decisions based on this data.

Read our methodology - how this data is sourced, computed, and verified.

Data sources used on this page

USPTO PatentsView - the disambiguated bulk patent-grant, assignee, and CPC data this page's figures are derived from. patentsview.org
Cooperative Patent Classification (CPC) - the joint USPTO/EPO classification scheme used to group patents by technology area. cooperativepatentclassification.org
USPTO Patent Public Search - the official interface to verify the status of any individual patent. ppubs.uspto.gov

Compiled by PlainPatent, US Patent Intelligence Editorial Process · May 15, 2026

Every figure on PlainPatent is rendered directly from USPTO source data, no number is typed in by an editor. This page draws directly on USPTO source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.