Nike RN and CA codes: what do they really mean on a football shirt?
Short answer: RN 56323 and CA 05553 are not authenticity codes. RN is a company number issued by the US Federal Trade Commission and CA is its Canadian equivalent: both only identify the company responsible for the garment, so they appear on thousands of different products and are easy to copy. To check a Nike shirt, start with the 9-digit product code on the inner tag, then compare the fabric, stitching and crest.
On the inner label of most Nike shirts, just below the "Made in…", two mentions come up every time: RN 56323 and CA 05553. Many buyers, and quite a few sellers on Vinted or eBay, present them as proof of authenticity, a bit like a unique serial number. It's a mistake of method that can prove expensive.
These two codes really do exist, they are legitimate, and they appear on almost all Nike clothing sold in North America. But their role has nothing to do with product authentication. This guide explains what RN and CA really are, why they are never enough to settle real versus fake, and above all what they are actually useful for once you know how to read them properly.
⚡ Quick answer
RN 56323 is Nike's manufacturer registration number with the US Federal Trade Commission (mandatory for textile labelling in the United States), and CA 05553 its equivalent issued by the Competition Bureau of Canada. They are legal company identifiers, printed on almost all Nike clothing, and therefore on many counterfeits too, which copy them without difficulty. They only confirm that a product presents itself as made by Nike, never that it really is. To authenticate a shirt, they must always be cross-checked with the product code (MPN), the AUTHENTIC tag and the visual clues (Swoosh, fabric, stitching).
At Pure Football Shirts, I authenticate every shirt before putting it on sale. Here's what you really need to know about these two codes, and where to focus your attention instead.
In this guide
What exactly is an RN number?
RN stands for "Registered Identification Number": an identification number issued free of charge by the Federal Trade Commission (FTC), the US federal consumer protection authority. It is governed by the Textile Fiber Products Identification Act and the Wool Products Labeling Act, two US laws that regulate clothing labels.
In practice, US law requires every textile garment to state on its label the fibre composition, the country of manufacture and the identity of the company responsible (manufacturer, importer or distributor). Rather than printing a full, sometimes long, company name on a small label, the FTC allows companies to use their RN number instead, a kind of legal shortcut.
A few rules worth knowing:
- An RN is free and is obtained on simple request from the FTC.
- The FTC assigns only one RN per company, whatever its products or brands.
- Using an RN is not mandatory : a brand can choose to print its full name instead.
- The RN of Nike, Inc. is 56323. This number is fixed: there is no "2018 RN" or "limited edition RN", contrary to what some marketplace sellers sometimes suggest.
And what does the CA number correspond to?
The CA number (CA Identification Number) is the Canadian equivalent of the RN. It is issued by the Competition Bureau of Canada, under the Textile Labelling Act. Like the RN, it allows a company to appear on the label as a code rather than a full name and address.
The format is always "CA" followed by five digits : for Nike, it is CA 05553. This number is also unique per company, optional and issued only once. It doesn't change with the season, the product line (shirts, shoes, accessories) or the factory that made the piece.
In short: RN and CA identify the brand, not the product. That's the fundamental difference to understand before going any further.
Where to find these codes on a Nike shirt
On a Nike shirt, RN 56323 and CA 05553 almost always appear on the composition/care label, the one that also shows the polyester percentage, the washing instructions and the country of manufacture. This label is sewn inside, usually at the bottom of the shirt near the hem, sometimes right next to or below the label carrying the product code (MPN, such as DX9822-568).
The display format varies slightly across years and ranges, but you will typically find a line like this:
MADE IN VIETNAM · RN 56323 · CA 05553
On vintage shirts, particularly those made before the end of the 1990s, these mentions may be absent, abbreviated differently, or replaced by the full name of the legal entity that made the shirt at the time (for example a subsidiary or a local licence partner, before Nike harmonised its labelling worldwide). Their absence on an old piece is therefore not a warning sign in itself.
Why these codes never prove authenticity on their own
This is the point most improvised authentication guides skip over, and yet it's the one that prevents the most errors of judgement:
RN 56323 and CA 05553 are public, fixed numbers, identical on all Nike clothing worldwide. They don't vary by season, collection or production factory. A shirt made in 2005 carries exactly the same numbers as a shirt released in 2026. This means two things:
- They can't date a shirt. Seeing "RN 56323" on a label tells you nothing about the year the piece was made.
- They can't tell a real shirt from a fake. Because these numbers are public and easy to find (a simple online search is enough), any counterfeiter can reproduce them exactly on a fake label. Their mere presence, correct to the digit, therefore guarantees absolutely nothing about the shirt's real origin.
A seller who highlights "RN56323 verified!" as a selling point is, in reality, offering no additional proof. It's a neutral clue: its presence is normal and expected, and its absence on a recent shirt is more suspicious than its presence is reassuring.
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How to check an RN number in the official FTC database
There is, however, one legitimate and useful use for these codes: checking that they really match the company stated. The FTC provides a free public database, the RN Database, which anyone can consult.
The process is simple:
- Go to the FTC's RN database and enter the number found on the label (for example 56323).
- Check that the associated company really is Nike, Inc. (or one of its registered legal subsidiaries).
- If the RN number shown on a shirt points to a completely different company with no link to Nike, that's a serious warning sign: either a label recycled from another garment, or an invented number.
This check has value: it confirms that the printed number isn't a pure invention. But it never replaces examining the product itself, since a counterfeiter can perfectly well copy a valid RN onto a fake label. In that case, the database check reveals nothing abnormal, even though the shirt is still a fake.
What you really need to check on a Nike shirt
Since RN and CA are only company identifiers and not product markers, serious authentication of a Nike shirt relies on other elements, presented in detail in my complete guide to the Nike label :
- The product code (MPN), such as DX9822-568, which identifies a precise model (club, season, version) and can be checked with an image search.
- The black "AUTHENTIC" tag at hip level, with its distinctive gold reflections on Player/Match versions.
- The technology tags (Dri-FIT ADV, Vaporknit, Aeroswift), found only on Pro versions.
- The visual clues : precision of the Swoosh, fabric quality, regularity of the stitching, accuracy of the crest and of the printing.
The right method is to cross-check all these elements against each other rather than rely on a single indicator. A shirt that shows consistent RN and CA numbers but has an untraceable product code, no AUTHENTIC tag and irregular stitching is still a fake, despite perfectly accurate registration numbers.
The questions I'm asked most about RN and CA
My Nike shirt shows RN 56323 and CA 05553: is it authentic?
These two numbers only confirm that Nike, Inc. is the company declared on the label. They appear on almost all Nike clothing, counterfeits included, because they are public and easy to copy. To judge real authenticity, you also need to check the product code (MPN), the AUTHENTIC tag and the visual details (Swoosh, fabric, stitching).
Does the RN number change with the year or model of the shirt?
No. RN and CA identify the company, not the product. Nike uses the same RN 56323 and the same CA 05553 on all its clothing, whatever the year, the product line or the factory. A 2005 shirt and a 2026 shirt carry exactly the same numbers.
My vintage Nike shirt has no RN/CA mention: is that suspicious?
Not necessarily. On older pieces, particularly before the end of the 1990s, labelling could follow other conventions or state the full name of the manufacturing entity rather than an RN/CA code. The absence of these mentions on a vintage shirt is therefore not, in itself, a sign of a counterfeit.
How do I check that an RN number really matches Nike?
The Federal Trade Commission provides a free public database, the RN Database, where anyone can enter an RN number and see the associated company. If the number on the label points to a company other than Nike, that's a warning sign. On the other hand, a correct RN doesn't guarantee authenticity on its own, since it can be copied onto a counterfeit.
Why expert verification makes the difference
RN and CA codes are useful to know so you understand what you're looking at on a Nike label, but they never replace a serious cross-check. That's exactly what I apply to every Nike shirt that enters my stock: checking the product code in reference databases, verifying the AUTHENTIC tag (gold reflections for Player versions), identifying the technology tags, and physically inspecting the stitching, fabric and printing.
You don't need to have bought from me to benefit: if you already own a Nike shirt and have a doubt, I can authenticate it and issue you an numbered Pure Football Shirts certificate of authenticity, from €9.99 , useful both for your own peace of mind and to add value to your piece if you resell it, particularly on Vinted.
To go further, find my complete method in the football shirt authentication guide, my complete guide to the Nike label, as well as my dedicated guides to spotting a fake Puma shirt and a fake Adidas shirt.
Matthieu Lapierre — Authenticator at Pure Football Shirts. I have been inspecting and certifying vintage and modern football shirts for several years, with particular attention to the labelling details specific to each manufacturer.
