Size Matters: How Law Firm Size Relates to Patent Quality

In an ideal world, every patent law firm, from a small practice drafting 50 patents a year to a large firm drafting thousands a year, would deliver patents for their clients that contain no errors. In reality though, patent drafting is complex and tedious work, and errors inevitably occur.

So as a client, how do you ensure the highest quality patent applications? When it comes to quality work and the prevalence of errors, does the size of the firm you choose matter? In a recent study of proofreading errors and firm size, we found that it just might.

Before we begin, let’s define how errors were determined for this analysis. As part of the Patent Bots annual quality rankings, we used advanced machine learning software to proofread a year’s worth of patents, more than 314,000 issued between April of 2024 and March of 2025. For this study, we focused on three error types – numbering errors, antecedent basis errors, and word support errors. We chose these specific errors because they are objective, can be determined with high accuracy, and any quality patent should not have them.

Using the proofreading results, each firm with at least 50 issued patents was ranked and assigned a quality score based on the prevalence of errors. Each firm was also categorized by size based on the number of issued patents. The number of firms in each size category is shown in the table below.

Small Firms Dominate the Top 10 Rankings

Each year as part of the rankings, we publish the names of the top 50 law firms to congratulate them on their excellent work. The table below shows the quality score and size categorization for the 10 firms that ranked highest based on the proofreading analysis. The quality score ranges from 0 to 100, with 100 being highest quality and 0 being lowest quality.

Of the top 10, small firms make up the majority: six are small, one is medium, and three are large. This has been the case for each of the six years that Patent Bots has computed quality rankings. (Note that the law firm list includes some companies because these companies are filing their own patents).

On the surface, it seems logical that smaller firms would dominate the top 10 rankings. When you have a smaller firm, it seems easier for the law firm to make sure that all patent attorneys are following a consistent process for patent proofreading or regularly using patent proofreading software. At a small firm, it should be easier to keep everyone aligned, whereas at a large firm, with hundreds of patent attorneys, it can be more challenging to ensure that each and every one is maintaining high-quality work.

Small Firms Rank Lower for Quality

After analyzing the top 10 firms, we wanted to see the distribution of firms with the lowest overall quality rankings. Because small firms dominate the top 10 rankings every year, we expected that large law firms would be more prevalent in the lower rankings. We were surprised that this was not the case.

To understand the lower quality firms, we computed a histogram of quality scores of all 710 firms, as shown in the graph below. The vertical axis is the number of firms in each decile. The horizontal axis is the quality score, so the firms on the right have the highest rankings with quality scores near 100, while the firms on the left have the lowest rankings with quality scores near 0.

The bottom decile is firms with quality scores from 0 to 10. The bottom decile includes 45 firms, and when broken out by size, it turns out that there are 30 small firms in this group, 15 medium firms, and only one large firm. This finding is opposite of what we expected, as here, the majority of firms in the lowest decile for quality are small firms.

When we analyzed the whole histogram by size, the data showed that small law firms, as denoted in blue in the figure below, skew to the left, towards the lowest quality end of law firms. The large law firms, shown in orange, skew to the right, meaning that on average, large law firms do higher quality work, and the medium firms, in red, are in between. So, overall, the data shows that, generally, smaller law firms have more patent proofreading errors in their work than large law firms.

Our team was quite surprised by the outcome of this analysis, particularly given the performance of small firms in the top ten. It doesn’t feel intuitive, given the availability and low cost of proofreading tools, not to mention that maintaining a consistent process seems as though it would be easier for smaller firms. We would love to hear your thoughts in the comments as to why you think small firms would have lower quality scores.

Regardless of firm size, proofreading remains a critical element of the patent application process, whether done with software or a second pair of eyes. In-house teams would be well served to monitor the work quality of their outside counsel, whether that firm is small or large.