A Manufacturer Part Number (MPN) is a unique alphanumeric code assigned by the company that makes a product, and you can usually find it printed on the product itself, stamped on a label, listed in the product’s documentation, or looked up through the manufacturer’s online parts catalog. The exact method depends on what type of product you’re dealing with, whether it’s a car part, an electronic component, a piece of computer hardware, or something you’re trying to list for sale online.
What an MPN Actually Is
An MPN identifies a specific product as it comes from the manufacturer. It’s different from a UPC or barcode (which is a retail identifier called a GTIN), and it’s different from a SKU, which is an internal tracking number a particular store assigns. The MPN is the manufacturer’s own code, and it stays the same regardless of which retailer sells the product. MPNs vary in length and format since each manufacturer creates its own numbering system, but they’re used globally across industries.
Knowing the MPN matters when you need to order an exact replacement part, verify compatibility, or list a product on platforms like Google Shopping, Amazon, or eBay that require it for proper identification.
Check the Product Itself
The fastest way to find an MPN is to look at the physical product. Manufacturers typically print or engrave the part number in one of these locations:
- Product labels or stickers: Look for a label on the back, bottom, or side of the item. The MPN is often listed next to fields like “Part No.,” “P/N,” “Model No.,” or simply “MPN.”
- Stamped or engraved text: On metal parts, hardware, and automotive components, the number may be stamped directly into the material.
- Printed circuit boards: Electronic components often have the part number printed on the board or the component housing itself.
- Packaging: If you still have the original box, the MPN is almost always printed on it, often near the barcode.
Don’t confuse the MPN with the serial number. A serial number is unique to your individual unit, while the MPN is the same for every unit of that product model.
Find It in Product Documentation
Owner’s manuals, spec sheets, invoices, and packing slips frequently list the MPN. If you purchased the item online, check your order confirmation email or your account’s order history on the retailer’s website. Many retailers display the MPN on the product listing page itself, sometimes under a “Specifications” or “Details” tab.
Look It Up on the Manufacturer’s Website
Most manufacturers maintain online product catalogs where you can search by product name, model, or category to find the official part number. If you know the brand and the general product description, searching the manufacturer’s site directly is often the most reliable route. Many sites let you filter by product line, year, or application to narrow down the exact part.
Finding an MPN for Vehicle Parts
Auto parts are one of the most common reasons people search for MPNs, and the process has an extra step because you need to match the part to your specific vehicle. Start by locating your Vehicle Identification Number (VIN), a 17-character code unique to your car. You can find your VIN in a few common spots: the lower corner of the windshield on the driver’s side, the inside of the driver’s door frame, or inside the engine bay.
Once you have the VIN, enter it into an electronic parts catalog for your vehicle’s make. Manufacturer-specific parts catalogs are available online through sites like epc-data.com and similar tools. After entering the VIN, the catalog will display your vehicle’s features and a schematic diagram organized by sections (engine, body, electrical, etc.). Navigate to the section where your part belongs, click on the specific component in the diagram, and the catalog will display the OEM part number. That number is your MPN.
If you don’t want to use an online catalog, a dealership’s parts department can look up the MPN for you using the same type of system. Just bring your VIN and a description of the part you need.
Finding an MPN for Computer Hardware
For internal computer components like processors, RAM, or motherboards, you can sometimes identify part information without opening the case. On Windows, open Command Prompt (type “cmd” in the Start menu), then type “set” and press Enter. This displays system environment variables, including the PROCESSOR_IDENTIFIER string, which tells you the processor family and architecture. For more detailed hardware identification, the System Information tool (type “msinfo32” in the Start menu) lists model numbers for many installed components.
For the exact MPN of a specific component like a RAM stick or hard drive, though, you’ll typically need to either check the original purchase records or physically inspect the part. Labels on RAM modules, SSDs, and hard drives almost always include the manufacturer’s part number.
Using the MPN When Selling Online
If you’re listing products on marketplaces or through Google Merchant Center, you’ll need the MPN alongside the brand name to properly identify your product. Google uses the MPN as one of its unique product identifiers, and submitting it correctly helps your listing appear in relevant search results. If you manufacture the product yourself and haven’t assigned an MPN, you can create your own unique identifier to use in the MPN field.
One important rule: don’t substitute a SKU or internal store code where the MPN is requested. SKUs are retailer-specific numbers that mean nothing outside your own inventory system, while MPNs are recognized universally for that product.