Short answer: yes. If you sell clothing in the US, the label inside the garment isn't optional. Two sets of FTC rules decide what goes on it, and getting them wrong can hold up a shipment or a retailer approval.
Here's what's required, where it goes, and how to design labels that comply and still look like your brand.
This is a practical guide, not legal advice. For anything unusual, such as wool, fur or children's sleepwear, check the FTC's clothing labeling guide and CPSC guidance, or ask a compliance specialist.

Brand label and tags for 4WBW Intimates, designed as one system.
What the RN does
US labeling law says every garment has to tell the customer who is responsible for it. You can do that one of two ways:
your full business name, exactly as it appears on your invoices, or
your RN, written as "RN" followed by the number (for example, RN 123456).
That's all the RN is: a short way to identify your company on a small label. Anyone can type the number into the FTC's public RN search and see whose it is.
Do you need an RN number?
No, it isn't required. Your business name works just as well. Brands get one anyway because:
It's short. "RN 123456" fits on a small neck label or a printed tagless label. A long legal name often doesn't.
It looks established. Buyers, factories and licensors are used to seeing it, and a label without one can look like a first-time brand.
It keeps your legal name off the product. That matters if your LLC name is different from your brand name.
Who can apply, and what it costs
Only US-based businesses can get an RN. A foreign factory can't apply for you.
It's free. If a website charges you to "register your RN," you're paying a middleman for something the FTC does at no cost.
One RN per company. You don't need a new number for each product line or each brand you own.
It's fast. The FTC usually processes online applications within about three business days and emails you the number.
Apply directly through the FTC's RN system at rn.ftc.gov. You'll need your legal business name, address and business type (manufacturer, importer, wholesaler or retailer).
Can you use someone else's RN?
Sometimes, yes. The label can carry the RN or business name of a US company that's directly involved in marketing the product, such as the importer, distributor or retailer.
That's why private-label goods often carry the retailer's RN, and why an overseas factory making your line should put your RN or name on the label, not theirs. When we design labels for a licensed or private-label program, the first thing we confirm is whose RN goes on the label. That decision belongs to the retailer or licensee, not the factory.
Where the RN goes on the label
The RN usually sits on the same label as the fiber content and country of origin, often the neck label or the first side-seam label. It doesn't have to be the care label, but most brands keep all the required information together so the factory gets one clear label spec.
A clean, buyer-ready label usually reads like this:
BRAND NAME
60% Cotton / 40% Polyester
Made in Vietnam
RN 123456
Care instructions go on the permanent care label. For the full list of what has to be on it, see Do I Legally Need a Care Label?
Keep it up to date
If your business name, address or legal structure changes, you have to update your RN registration. The FTC can cancel an RN that isn't kept current, and you don't want to find that out when a shipment is waiting on reprinted labels.
Quick answers
Is an RN number a trademark? No. An RN only identifies the company responsible for the garment. It gives you no rights to your brand name. That takes a trademark.
Can I put the RN on my hang tag instead of the label? Put it on the sewn-in label. Hang tags come off at the register, and the sewn label is where retailers, customs and the FTC expect to find it. Your hang tag can repeat it. See What Goes on a Hang Tag.
What's a WPL number? An older FTC number for wool products. They aren't issued anymore, but existing ones still work the same way as an RN.
Making labels for your line? Designland designs neck labels, care labels, hang tags and full trim packages your factory can produce, and that make your line look ready for retail. See our hang tag & label design service or book a free 20-minute intro call.