How to Tell Whether a UL Certification Is Real: Verify a Fire Door Viewer in Three Steps

Door viewers on the market are often marked “UL” or “fire-rated,” but a marking is not proof of certification. Counterfeit UL Marks and even forged test reports do exist: UL Solutions has publicly warned about fake test reports issued in its name. When you buy fire door viewers, these three steps let you check for yourself.

Step 1: Check the UL Mark on the product itself

In its Question Corner column and its Marks and Label Hub, UL explains that a genuine UL Listing Mark has four elements:

1. the UL symbol in a circle;
2. the word “LISTED”;
3. the product name;
4. a control number (or an issue or serial number).

UL also uses newer Enhanced and Smart Certification Marks: the UL Mark with an attribute such as “SAFETY,” country codes and a unique identifier, sometimes with a QR code. They do not necessarily show the word “LISTED” or a control number; if you see one, verify it in UL’s official database as in Step 2.

In addition, UL requires listed products to carry a marking that identifies the certified manufacturer: the company name, a trademark, or the manufacturer’s UL File Number.

Step 2: Look up the File Number in UL’s official database

The most reliable check is to search UL’s official certification database, UL Product iQ, directly. Search by the UL File Number your supplier gives you (for example, R13709) or by the category code HAAU (Fire Door Viewers), and confirm three things:

1. the listed company matches your supplier, or your supplier can clearly explain how the two are related;
2. the category is “Fire Door Viewers”;
3. the model you are buying is on the list of listed models.

Basic searches in UL’s official database are free; the more detailed category guide documents require a free account.

Step 3: If in doubt, ask UL

UL’s official database notes that anyone can contact the UL Customer Experience Center to check whether a certification is valid: phone 1-877-854-3577, email CEC@ul.com.

Common warning signs of a fake certification

According to UL, all of the following should raise suspicion:

• the “U” and “L” in the mark sit side by side instead of being staggered;
• there is no control number (or issue or serial number), or the mark says “Approved” or “Pending” instead of “LISTED” (the newer Enhanced and Smart Marks follow a different format; see Step 1);
• the UL Mark is printed only on the box, not on the product itself;
• the box or the product mentions UL but has no marking that identifies the certified manufacturer (company name, trademark or UL File Number);
• poor workmanship or packaging.

From purchasing practice, we would add three more warning signs:

• the supplier can show only a photo or PDF of a certificate, but no File Number that can be found in UL’s database;
• the listed company does not match the supplier, and the supplier cannot explain the relationship;
• the model you want to buy is not on the list of listed models.

ABTI as an example

ABTI’s UL File Number for fire door viewers is R13709, which anyone can look up in UL Product iQ: listed company Yu Hong Xing Co Ltd (the registered company name behind ABTI; see Company), category Fire Door Viewers, listed models A800-01 to A800-18.

The UL label on our listed fire door viewers shows exactly the four elements from Step 1: the UL Mark with the word “LISTED,” the product name “FIRE DOOR VIEWER,” and the control number “73S8.” It also carries the UL File Number “R13709,” which leads back to the listed company in UL’s official database. For how our website models map to UL models, see ABTI’s UL Fire Certification and Model Cross-Reference.