ATP Certificate and FRC Class Explained: What the Letters on a Reefer Trailer Mean
Look at the front corner of a refrigerated trailer and you’ll usually find a plate with a short code: FRC, FNA, IR, and a handful of others. It looks like technical shorthand because it is. This is the ATP certificate marking, and it tells you, precisely, what that trailer is legally allowed to carry. This guide explains what the letters mean, why FRC sits at the top of the scale, and how to check a carrier’s certificate is actually current.
What the ATP agreement is
ATP stands for the Agreement on the International Carriage of Perishable Foodstuffs, a UNECE treaty dating to 1970 and now covering transport across most of Europe and beyond. It exists for one reason: to make sure a vehicle claiming to be refrigerated actually holds the temperature it claims to hold, tested and certified, not just described on an invoice. Fresh produce that hasn’t been processed falls outside its scope; almost everything else that needs temperature control does not.
The classification system
ATP equipment is sorted by two things: how it’s insulated, and how it’s cooled. Combine them and you get a short code.
Insulation letter:
- N = normally insulated
- R = heavily insulated (the standard for most modern reefer trailers)
Cooling method letter:
- F = mechanically refrigerated (an active refrigeration unit)
- (Insulated-only equipment with no active cooling carries just IN or IR, with no F)
Temperature class letter, which sets the coldest guaranteed internal temperature the unit must maintain regardless of outside heat:
| Class | Minimum guaranteed internal temperature | Typical cargo |
|---|---|---|
| A | 0°C | Chilled goods, dairy, some produce |
| B | −10°C | Some frozen goods, ice cream at moderate depth |
| C | −20°C | Deep-frozen goods, frozen meat and fish |
| D | −20°C, with stricter insulation requirements | Similar to C, higher insulation standard |
Put the letters together and FRC reads as: mechanically refrigerated (F), heavily insulated (R), capable of holding at least −20°C (C). It’s the combination most carriers aim for, since it covers chilled and frozen cargo with one trailer.
Why FRC is the gold standard
FRC isn’t a marketing term; it’s the classification that gives a trailer the widest cargo range. An FRC-certified trailer can carry chilled goods at +4°C just as legally as it carries frozen fish at −20°C, provided the certificate is current. A trailer certified only FNA, by contrast, is limited to the 0°C to roughly +12°C band and cannot legally carry deep-frozen cargo, whatever temperature its display happens to show.
This matters at a roadside inspection. An inspector checking a shipment of frozen goods against an FNA-only trailer isn’t checking a technicality; the trailer is not certified for that cargo, certificate or no certificate on board.
How to read an ATP plate
The plate sits at the top front corner of the trailer body, both sides, in dark lettering. It states the classification code (FRC, FNA, and so on) and an expiry date. If the date has passed, the equipment is not legally certified for ATP-regulated cargo, regardless of how well the refrigeration unit still performs.
Checking a carrier’s ATP validity
An initial ATP certificate runs for six years. It can be renewed, typically to nine years by an approved test centre and up to twelve or beyond through a testing station, depending on the equipment class and jurisdiction. Older trailers, particularly those pushing toward the upper end of that range, face a more demanding technical retest, and equipment that once held an FRC class can be downgraded to a fresh-only class such as FNA if it no longer meets the frozen-cargo insulation standard. A trailer’s age alone doesn’t disqualify it. What matters is whether the plate on the trailer, the expiry date on it, and the temperature your cargo needs all line up.
Need a trailer certified for a specific temperature class? See our refrigerated transport service, or check the temperature ranges required for your product in our full reference table.
Frequently Asked Questions
An initial certificate runs six years, with renewal periods extending it further depending on the class and testing route, up to roughly twelve years or more before a full technical requalification is required.
Yes, for the international carriage of perishable foodstuffs covered by the agreement between ATP contracting parties, which includes all EU member states. Domestic-only transport within a single country may fall under separate national rules.
FRC is mechanically refrigerated, heavily insulated, and certified down to at least −20°C, covering both chilled and frozen cargo. FNA is mechanically refrigerated, normally insulated, and limited to the 0°C to roughly +12°C band, suitable for chilled goods only.
ATP certification applies to the vehicle’s temperature-holding capability, which pharmaceutical transport also relies on, but GDP compliance for medicines adds further requirements beyond ATP alone, covering calibration, monitoring and documentation. Our guide to pharmaceutical transport in Europe covers that layer in full.
The equipment is no longer legally certified to carry ATP-regulated cargo, regardless of how the refrigeration unit is performing. Inspectors check the plate and the paperwork; an expired certificate is treated the same as no certificate at all.
The letters on that plate are the whole point of the certificate: they tell you, before you load a single pallet, exactly what the trailer is allowed to carry and at what temperature. Check the class against your cargo, check the date against today, and the rest of the paperwork follows from there.
