how to prove the date of purchase if I haven't registered my product immediately after I bought it?
PS. I can't find the bill.. I only remember the exact date because I set up office in the same shop and they sent me an email confirmation..
MacBook
If you purchased your MacBook directly from Apple or an Apple Authorized Reseller, the notebook was automatically registered with Apple. In addition, if you signed in with your Apple ID, you had the opportunity to include this device as associated with that ID.
How you prove the purchase date is to retain the original sales receipt when you did buy it.
Ref:
Then register the product with your best guess for the data of purchase? The serial number can tell when the unit was manufactured roughly, but cannot tell when it is sold.
how to prove the date of purchase if I haven't registered my product immediately after I bought it?
