How to add manufacturer's part number to products

[Seacut]

I need to add MPNs to my products, but as far as I can tell, Shopify doesn't have a dedicated way to do so. I also have barcodes and internal SKUs for each product, so I can't overwrite those values. Should I just add my MPNs as tags, or is there a better field to use?

[LoveLouMae]

There is a dedicated MPN Box if you have google as an app on your shopify thats where the MPN value goes,  its needed in there to get your products to list on google. 

[udizisser]

I have the google and youtube app and have a product even listed in the youtube store on my channel. I can see it also in the merchant center where I can add MPN but don't see this field in the Shopify product page.. I only see the Barcode (ISBN, UPC, GTIN, etc.)
This is important for google listings if you don't have barcode.