Gluten-Free Labelling Requirements: UK vs EU vs US Compared

"Gluten-free" is one of the most valuable claims a food business can make — but it is also one of the most tightly regulated. For coeliac disease sufferers and those with non-coeliac gluten sensitivity, a gluten-free claim is not a lifestyle preference but a medical necessity. Misusing or misrepresenting a gluten-free claim can cause serious harm, and regulators in all major markets take it seriously.

This guide compares the gluten-free labelling rules in the UK, EU, and US, and explains what food businesses selling online need to know.

What Is Gluten and Why Does It Matter?

Gluten is a group of proteins found in wheat, rye, barley, and their derivatives (including spelt and kamut). Oats do not naturally contain gluten but are frequently contaminated with it during growing and processing. For people with coeliac disease — an autoimmune condition affecting approximately 1 in 100 people in the UK — consuming even small amounts of gluten triggers an immune response that damages the small intestine. There is no treatment other than a strict lifelong gluten-free diet.

The threshold for "gluten-free" claims matters enormously because even tiny amounts of gluten can cause harm to coeliac sufferers.

EU Gluten-Free Rules (Regulation 41/2009 / Regulation 828/2014)

In the EU, gluten-free claims on food are governed by EU Regulation 828/2014, which replaced Regulation 41/2009 and came into force in July 2016. The rules:

"Gluten-free" can only be used for foods containing 20 mg/kg (20 ppm) of gluten or less
"Very low gluten" can be used for foods specially formulated for coeliacs containing between 21 and 100 mg/kg of gluten
These limits apply to the food as sold to the consumer
The claim must not mislead the consumer — foods that are naturally gluten-free by nature of their ingredients (e.g., a plain rice product) can use the claim, but should ideally qualify it to avoid confusion

Importantly, the EU rules do not specify any particular testing methodology — businesses must demonstrate compliance through appropriate testing, with the R5 ELISA method being the most commonly used and widely accepted.

UK Gluten-Free Rules

Post-Brexit, the UK retained EU Regulation 828/2014 into UK domestic law. The gluten-free threshold remains 20 mg/kg (20 ppm). The "very low gluten" category (21-100 ppm) also remains, though it is rarely used in practice in the UK market.

Natasha's Law (effective October 2021) overlaps with gluten-free labelling for PPDS food — cereals containing gluten must be emphasised in the ingredients list regardless of whether a gluten-free claim is made. A product claiming "gluten-free" must still list ingredients accurately, including any gluten-containing cereals if present (which would, of course, be incompatible with a genuine gluten-free claim).

US Gluten-Free Rules (FDA Rule 21 CFR 101.91)

In the United States, the FDA published a gluten-free labelling rule in 2013, which became mandatory in August 2014. Key points:

"Gluten-free" (and equivalents like "free of gluten," "without gluten," "no gluten") can only be used for foods that contain less than 20 ppm of gluten
This applies to naturally gluten-free foods, foods from which gluten has been removed, and foods formulated without gluten-containing ingredients
The FDA specifically chose 20 ppm because it is the lowest level that can be reliably detected with validated testing methods and represents a safe threshold for most coeliac sufferers
The FDA does not have a "very low gluten" category — 20 ppm is the sole threshold

USDA-regulated foods (meat, poultry, certain egg products) follow the same 20 ppm standard, adopted in 2020.

Oats: The Complicating Factor

Oats are naturally gluten-free but are almost universally contaminated with wheat during growing, harvesting, transport, and processing. The regulatory picture on oats differs between markets:

EU/UK: Pure oats (uncontaminated, certified gluten-free oats) can be included in gluten-free products, provided the finished product still meets the 20 ppm threshold. Some EU countries have stricter guidance, and Coeliac UK recommends that some coeliac sufferers avoid even certified oats due to a different immune response
US: FDA's gluten-free rule covers oats that have been processed to remove gluten contamination, provided the 20 ppm limit is met in the finished product

If your gluten-free product contains oats, declare this prominently — many coeliac shoppers look for "gluten-free, including oats" or "gluten-free, no oats" as part of their purchasing decision.

Testing and Substantiation

Whatever market you sell in, a gluten-free claim must be substantiated. This means:

Ingredient verification — all ingredients must be confirmed gluten-free by your suppliers
Facility assessment — cross-contamination risks in your production facility must be assessed and controlled
Product testing — finished products should be tested using a validated method (R5 ELISA is the gold standard) at a frequency appropriate to your production volumes and risk profile
Records — keep records of ingredient allergen declarations, facility cleaning validation, and product test results

Communicating Gluten-Free Claims Online

On your Shopify store or food website:

Use "gluten-free" only for products that meet the relevant threshold for your market
If you sell to both UK/EU and US markets, the 20 ppm threshold is consistent — no conflict
If your gluten-free products contain oats, state this clearly
Where cross-contamination risk exists (e.g., produced in a shared facility), consider whether a "may contain gluten" advisory is needed — and whether it is compatible with your gluten-free claim (in most cases, if genuine cross-contact risk exists, a gluten-free claim is not appropriate)
Consider displaying your testing results or certification on product pages — this builds significant trust with coeliac consumers

Third-Party Certification Schemes

Third-party gluten-free certification provides an independent layer of assurance beyond a business's own testing and controls. In the UK, Coeliac UK operates the Crossed Grain trademark, which is one of the most recognised gluten-free symbols among UK consumers. To use it, businesses must apply, meet the 20 ppm threshold, and undergo ongoing auditing. The symbol carries significant trust weight on product packaging and on product pages within online stores, particularly among newly diagnosed coeliac shoppers who are still learning which brands they can rely on.

In the US, the Gluten-Free Certification Organization (GFCO) operates a widely recognised programme with a stricter internal threshold of 10 ppm — below the FDA's mandatory 20 ppm — which provides additional reassurance to the most sensitive consumers. The National Celiac Association and other bodies also offer certification programmes. For food businesses selling into the US market, carrying one of these marks on product listings can meaningfully differentiate your products in a competitive gluten-free category, where consumer trust is hard-won and easily lost.

For online food businesses, displaying certification logos on Shopify product pages is a straightforward way to communicate compliance credentials without requiring customers to read through technical detail. Alongside certification marks, linking to your allergen and dietary information — including a full allergen matrix for your product range — reinforces that your business takes food safety seriously. Tools like Allergen Matrix make it easy to present this information professionally and consistently across every product listing on your store.

Managing Gluten-Free Claims Across a Mixed Product Range

Many food businesses sell a combination of gluten-free and non-gluten-free products, which introduces complexity that purely gluten-free brands do not face. The key challenge is preventing cross-contamination during production — but it is equally important to prevent confusion in how products are presented online. If your Shopify store sells both gluten-containing and gluten-free variants of the same product, your product pages must make the distinction unambiguous. Customers with coeliac disease are scanning quickly for reassurance, and any ambiguity can either cost you a sale or, worse, result in a customer purchasing the wrong product.

Your internal processes matter as much as your labelling. If gluten-free products are produced on shared equipment, you must validate your cleaning procedures to confirm that gluten residues are reduced below 20 ppm between production runs. This is not a one-time exercise — it requires periodic re-validation, particularly when you change ingredients, equipment, or cleaning chemicals. You should also consider the segregation of raw ingredients in storage, since flour and other gluten-containing powders can travel significant distances through air currents in a production kitchen or facility.

Document everything. Regulators and certification bodies expect businesses making gluten-free claims to hold records that demonstrate ongoing compliance — not just a single historical test result. This documentation should include supplier allergen declarations for every ingredient, records of facility cleaning validation, batch testing results, and any corrective actions taken when anomalies were identified. Keeping this documentation organised and retrievable is a basic requirement for any food business making a gluten-free claim, whether you are a sole trader making products at home or a larger operation with a dedicated production facility.

What to Do When Your Recipe or Supplier Changes

Recipe and supplier changes are among the most common routes by which a previously compliant gluten-free product becomes non-compliant — and businesses often underestimate the allergen implications of what appear to be minor changes. If you switch to a new supplier for any ingredient in a gluten-free product, you must obtain a fresh allergen declaration from that supplier before you begin using their ingredient. Do not assume that a product with the same name and description from a different supplier carries the same allergen profile. Manufacturing practices vary, and a supplier who does not handle gluten on their site today may introduce it in future.

Reformulation presents similar risks. Adding a new ingredient, changing the proportion of an existing ingredient, or altering your production method can all affect your product's gluten status. Any reformulation should trigger a formal review of your allergen risk assessment for the affected product, followed by updated testing where appropriate. This is particularly important if the reformulation involves any ingredient that is naturally associated with gluten-containing cereals, such as modified starch, malt flavouring, or certain emulsifiers, which can have variable gluten content depending on their source.

Equally important is updating your online product listings promptly whenever a change occurs. Outdated product information on a Shopify store is a genuine compliance risk — a customer who purchases a product based on a gluten-free claim displayed on your website is entitled to rely on that claim being current and accurate. Build a workflow into your recipe change process that includes updating your product descriptions, ingredient lists, and allergen summaries as a mandatory step before the changed product goes on sale. Automated allergen management tools can help flag when product data may be out of date, reducing the risk of stale claims persisting on live product pages.

Summary

Gluten-free labelling is tightly regulated across all major markets, with a consistent 20 ppm threshold in the UK, EU, and US. Businesses making this claim must be able to substantiate it through ingredient verification, facility controls, and product testing. Online food businesses should communicate their gluten-free credentials clearly and honestly on their product pages.

Ensuring your allergen and dietary claim information is accurate and consistently displayed across your Shopify store is straightforward with the right tools. Explore our range of allergen compliance apps at saltai.app to keep your food website compliant and trustworthy.

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Gluten-Free Labelling Requirements: UK vs EU vs US Compared