When is swimwear not swimwear according to the tariff book?

Updated May 2026.

Are you swimming through a sea of regulation and HS codes when it comes to classifying popular Summer products such as swimwear?

You may think that swimwear is swimwear, how many varieties can there be. A lot, let us tell you.

Here, we dive into the specifics of determining the correct tariff codes for various swimwear items, focusing on bikinis and swim shorts for men, and the newest entrant to the market, period swimwear, which carries its own surprising classification.

If you’re interested in the classification of other Summer products, take a look at our camping blog which breaks down how to classify other popular Summer items.

Bikini sets: Clear waters for classification

Let’s first take the example of a complete bikini set, consisting of both the top and bottom. This set falls under the category of swimwear in Chapter 6112.

According to the World Customs Organization (WCO) explanatory notes, swimwear includes “one piece or two-piece bathing costumes, swimming shorts, and trunks, whether or not elastic.” Therefore, a bikini set made from knitted fabric (87% Polyamide and 13% Elastane) fits snugly into this classification. The appropriate tariff code for such a set is 6112419000, with a duty of 12%.

Solo bikini tops: A different tide

Classification becomes trickier when dealing with bikini tops sold separately. A bikini top with defined cup definition, even if crafted from the same fabric as a complete set, does not qualify as swimwear under Chapter 6112. Instead, it is classified as a brassiere under tariff code 6212109000, attracting a duty of 6%. The key differentiator here is the design element: if the top is designed to mold and support the bust with defined cups, it falls into the bra category.

Similarly, a bikini top without defined cups also does not make the cut as swimwear. Lacking the necessary features to be classified as a bra, this item is categorised under “Other Garments” with tariff code 6114300000, subject to a 12% duty. This distinction is crucial for importers to avoid misclassification.

Bikini bottoms: Smooth sailing

In contrast, bikini bottoms sold separately can still be classified as swimwear. They fall under the same tariff code as a complete bikini set (6112419000) with a 12% duty. The WCO notes clearly state that swimwear includes trunks, which by interpretation and BTI rulings, extends to bikini bottoms. This provides a clear and consistent classification path for these items.

Swim shorts: Navigating the details

Classifying swim shorts presents its own set of challenges. For instance, swim shorts with non-fastening pockets, despite having an inner brief and elasticated waistband, do not qualify as swimwear under Chapter 6112. Instead, they fall under men’s shorts with tariff code 6203439000, attracting a 12% duty. The UK’s Tariff Garment Guide specifies that for swim shorts to be classified as swimwear, pockets must have a firm fastening system like zippers or Velcro.

On the other hand, swim shorts that meet these criteria, featuring zip fastening pockets, do qualify as swimwear. These shorts are classified under tariff code 6211110000, with a 12% duty, reflecting their compliance with the detailed requirements set out in the UK guide.

Period swimwear: a new current

Period swimwear is one of the newest product categories to land in importers’ ranges, and it does not classify where you might expect. An ordinary women’s swimsuit sits in Chapter 61 or 62, but a period swimsuit can fall under heading 9619, the same heading as sanitary towels, tampons, napkins and similar articles.

Following an Advance Tariff Ruling issued by HMRC on 17 March 2026 for a major UK retailer, a ribbed period swimsuit is classified to commodity code 9619005010, with UK duty of 0% and EU duty of 10.5%. The same item would previously have been classified to 6211120000 at 12% UK and EU duty. The duty difference is significant, but it hinges entirely on the construction.

The deciding factor is that the swimsuit is specifically designed with a special built-in gusset designed to absorb and lock in heavy period flow for a leak-free finish. The ruling rests on a three-layer gusset construction: a moisture-wicking comfort layer to keep the wearer feeling fresh and dry, a light absorbent layer that absorbs up to 12ml of fluid and neutralises odour, and an anti-leak layer that prevents leaks and stains. Without that absorbent gusset, the same garment stays in Chapter 61 or 62 as ordinary swimwear.
This mirrors the treatment of period knickers, which were reclassified from heading 6108 (underwear briefs) to 9619. Period swim briefs follow the same path: a Binding Tariff Information ruling classifies a period swim brief to 9619 as well.

The lesson for importers is that absorbent period products are classified by what they are designed to do, not by where they are worn. A period swimsuit is treated as a sanitary article first and swimwear second.

Precision classification is key

In the realm of customs classification, precision is key. Understanding the detailed guidelines and explanatory notes ensures accurate tariff code assignments, helping avoid costly errors. For importers dealing with swimwear, grasping these nuances can streamline the process and ensure compliance.

At TariffTel, we have delved into the intricate terms associated with products, and designed our Item Types in our customs classification solution to be user-friendly. That now includes emerging categories like period swimwear, so the distinction between a 9619 sanitary article and a Chapter 61 or 62 garment is captured at the point of classification. We eliminate the need for extensive research when classifying and reduce the risk of misclassification. This ensures your classification is accurate, done quickly and that you adhere to regulatory standards.

Want to understand more about classifying Summer products? Read our BBQ blog