CAT Serial Number Lookup: Find Your Year and Model

A Cat serial number lookup has one trap: Caterpillar does not put a year code in the serial number or the PIN. Machines built from the first quarter of 2001 carry a 17-character PIN whose last 8 characters are the serial number, a 3-character prefix plus a 5-digit sequence. The build date comes from Cat's records or the plate.

At a Glance

• Two formats: machines built from the first quarter of 2001 carry a 17-character PIN. Older machines, and components such as engines, transmissions and axles, use an 8-character serial number.
• The part that matters: characters 10 to 17 of the PIN are the serial number. The first three of those are the serial prefix that Cat's parts and service books are searched by.
• Where to look: on Cat excavators and mini excavators, the PIN plate is on the front of the machine, close to the operator compartment.
• The year: not encoded anywhere in the PIN. Read it from the plate where one is fitted, or look up the build date in Cat SIS.
• For parts: one model can have several prefixes, and parts change at serial breaks, so always quote the full serial number.

Where Is the Serial Number on a Cat Excavator or Mini Excavator?

Caterpillar's Operation and Maintenance Manuals use the same sentence for full-size and mini excavators: "The PIN plate is positioned on the front of the machine, close to the operator compartment." It appears in the 325F L excavator manual (SEBU9320, 2019) and the 300.9D mini excavator manual (SEBU8740, 2020). Start at the front of the machine and work around the operator station before you open any panels.

The plate carries more than the serial number. On the 300.9D it lists:

• Model and build: the sales model, such as 300.9D.
• Product Identification Number: 17 characters on machines from the first quarter of 2001.
• Month and year of manufacture: a separate plate, fitted only where local regulations require it.
• Regional certification plate: on machines certified for the European Union, a CE plate attached to the PIN plate is stamped with the year of construction.

Published identification guides add two more places to check on excavators. Some models carry a second serial plate in the cab, under the seat or on the shelf behind the operator, and many Cat mini excavators have the full PIN stamped into the frame near the plate. If you are still working out which mini you own, our guide to CAT mini excavator sizes and models explains how the model numbers map to machine size.

Where Is the Serial Number on a Cat Skid Steer or Compact Track Loader?

Our guide to CAT skid steer models covers where the PIN plate sits on Cat skid steers and track loaders, and how to read the model suffix, so we will not repeat it here. What it does not cover is what the plate tells you once you find it.

• PIN plate fields: the B3-series skid steer manual (SEBU8495) lists the model, build, PIN, a bar code and a month and year of manufacture plate where required.
• Engine serial plate: on the engine itself, separate from the machine PIN.
• Engine and chassis plate: on 216B3 machines with prefix PWK and 226B3 machines with prefix DXZ, the same manual describes an extra plate showing the engine number, chassis number and month and year of manufacture.

On machines that have it, that last plate states the build month and year outright. On most others, the year takes one of the methods further down this page.

Where Is the Serial Number on a Cat Wheel Loader, Backhoe or Dozer?

Cat's Operation and Maintenance Manuals include a section called "Plate Locations and Film Locations," and that page is the authority for your exact model. For older wheel loaders, backhoes and dozers, published equipment identification guides place the plate in these spots:

Those guides stop at the G and H series wheel loaders and D-series backhoes, so on newer equipment confirm with the manual. For backhoe model history, see our Caterpillar backhoe models and parts guide.

Where Is the Engine Serial Number on a Cat Machine?

The engine has its own serial number, and Cat treats it as a component, not a machine. Every Cat manual we reviewed states that "engines, transmissions, axles, and work tools will continue to use an 8 character Serial Number (S/N)," even on machines with a 17-character PIN. The 325F L manual simply says the engine serial number label "is located on the engine."

• Format: 8 characters, a 3-character prefix plus a 5-digit sequence. Cat Publications notes it is usually labeled "Serial Number," "S/N" or "SER. NO."
• When you need it: engine filters, gaskets and service parts are looked up against the engine.
• Repowered machines: if the engine has been replaced, its serial number will not match the machine's original build records.

Record both numbers before you order. The Cat parts store accepts either a machine or an engine serial number.

What Does the 17-Character Cat PIN Actually Mean?

Caterpillar splits the 17 characters into four sections under ISO 10261, the identification standard for non-road machines. The names below are quoted from the Foreword of Cat's Operation and Maintenance Manuals.

Take the example CAT0420DCFDP02567, printed in a published identification guide. CAT is the manufacturer code, 0420D the machine descriptor, C the check character and FDP02567 the serial number. Within that serial, FDP is the prefix and 02567 is the sequence number.

• Serial prefix: Cat Publications defines it as "the first 3 characters of the serial number, which is the last 8 characters (prefix/sequence ID) of the PIN." It can mix letters and numbers.
• Sequence number: the last five characters, numbers only, from 00001 to 99999.
• Machines built before the first quarter of 2001: keep the 8-character format, which is the prefix and sequence on their own.

Copy all 17 characters from the plate. A leading zero, such as the 0 in 0420D, is easy to drop, and a dropped character shifts every position after it.

Can You Tell the Year From a Cat Serial Number?

No. Many 17-character PINs use the 10th character as a model-year code, but Cat's does not: on a Cat PIN, the 10th character is the first character of the serial prefix. Reading it against another brand's year chart gives a confident, wrong answer.

Use one of these instead:

1. Read the plate. Cat PIN plates have a year of manufacture field (month and year on newer plates), filled in where local regulations require it. Machines certified for the European Union also carry a CE plate stamped with the year of construction.
2. Look up the build date in Cat SIS. The Cat Help Center's steps: sign in to your parts.cat.com account, select SIS from the main menu and enter the serial number. The model, serial number and build date appear under Product Configuration.
3. Ask a Cat dealer. Give them the full PIN rather than the model, so they can look up that specific machine.
4. Use a production table for vintage machines. TractorData, for example, lists the first Caterpillar D8 serial of 1937 as 1H1500 and of 1941 as 1H7693. Note the two-character prefix: very old Cat prefixes were not always three characters.

For parts, the year matters less than you might expect. Cat manuals state their coverage by serial prefix and range, not by model year, and parts listings flag changes as serial breaks.

What Is the Difference Between the Model Number and the Serial Number?

The model number is the sales model, such as 320D, 262D3 or 420F. The serial number identifies one machine, and its prefix is how Cat's parts and service books tell builds of the same model apart. One model often has several prefixes, which is why the model alone is not enough to order parts.

Cat writes coverage as a prefix and a starting sequence. The 325F L manual is for "XAA 1-UP," meaning machines with prefix XAA from sequence 1 onward. Quote the prefix and the full serial, not just the model, whenever you look up or order a part.

How Do I Order the Right Parts Using My Cat Serial Number?

The serial number gets you to the right OEM part number, and the OEM number is what an aftermarket replacement is matched against. When customers send us a Cat fitment question, the serial prefix is the first thing we ask for, and our own listings show why.

• Same model, different glass: our front upper glass replacing CAT 156-6472 lists fitment for the 320D among the C and D series excavators. Our E Series front upper glass replacing CAT 453-4794 also lists the 320D, but only with serial prefix GDP.
• Serial breaks inside a model: the D Series skid steer door glass replacing CAT 345-6230 listing notes a serial break on the 257D, 259D, 277D, 279D, 287D, 289D, 299D and 299D XHP.
• Series letters: the backhoe left hand upper door glass replacing CAT 205-9587 lists E and F series backhoes such as the 416E, 420E and 420F. The left front side glass replacing CAT 107-6144 lists G and H series wheel loaders from the 910G to the 938H.

A reliable order sequence:

1. Record the model, the full PIN and the engine serial number.
2. Look up the OEM part number by serial number in the Cat parts store at parts.cat.com, or in your machine's parts manual.
3. Match that OEM number to the replacement. Our aftermarket parts are built to meet or exceed OEM specifications, and each listing shows the OEM number it replaces.
4. Read the listing's fitment notes for serial breaks, then browse the full range of Caterpillar parts.

It is your responsibility to verify fitment before ordering. If you would like a second check, send your model and serial number to sales@partsonline.com and we will confirm it with you.

What If My Cat Serial Number Plate Is Missing or Unreadable?

Plates get painted over, damaged or removed, but the PIN is usually recorded in more than one place. Cat's manuals state that "the PIN plates and frame marking will display the 17 character PIN," so the frame is the first place to look.

• Frame stamping: identification guides report the full PIN stamped near the plate on many Cat mini excavators and newer crawler loaders, and on the right side ahead of the cab on 420 series backhoes. Clean off paint and grime before you try to read it.
• A second plate: some excavators carry one in the cab, under the seat or on the shelf behind the operator.
• The manual: Cat's Plate Locations and Film Locations section gives spaces to record the identification numbers. A previous owner may have filled them in.
• Paperwork: purchase documents, service invoices and dealer records often carry the full PIN.
• The engine serial number: still on the engine, and enough to look up engine parts.

Park on level ground, lower the attachments and stop the engine before you look around the frame and engine bay. If nothing turns up a number, email sales@partsonline.com with the model, photos of the machine and any part numbers on the old part, and we will help narrow it down. Consult a certified mechanic for any repair beyond a straight part swap.

Frequently Asked Questions

How to check a Cat serial number?

Find the PIN plate, which on Cat excavators sits on the front of the machine close to the operator compartment, and read the last 8 characters of the 17-character PIN. Enter that serial number in the Cat parts store at parts.cat.com to pull up the parts for your machine.

How can you tell the year of a Cat's serial number?

You cannot read it from the number, because Cat does not encode the year in the serial number or PIN. Sign in to parts.cat.com, open SIS and enter the serial number; the build date appears under Product Configuration.

What year is my Caterpillar?

Check the plate for a year of manufacture field or a CE plate, look up the build date in Cat SIS, or ask a Cat dealer with the full PIN. Vintage machines are dated with production tables matched to the serial number.

Can you tell a year by a serial number?

On some brands, yes. On a Cat machine, no: none of the 17 PIN positions is a year code, so use the plate, Cat SIS or a dealer.

Can I look up Cat parts by serial number?

Yes. The Cat parts store accepts a machine or engine serial number, and Cat Publications searches manuals by serial prefix or sales model. Once you have the OEM part number, match it to an aftermarket replacement and verify fitment by serial.

Is a Caterpillar PIN the same as a VIN?

It does the same job. Road vehicles carry a VIN, while Cat machines carry a Product Identification Number defined by ISO 10261 for non-road machines, and its last 8 characters are the serial number.

How do I look up an old Caterpillar serial number?

Machines built before the first quarter of 2001 use an 8-character serial: a 3-character prefix plus a 5-digit sequence. Much older crawlers used shorter prefixes, such as 1H on early Caterpillar D8 tractors, and are dated with production tables like TractorData's.