Warranty check by serial number

Thank you, I will

They will need the full serial number which can be a pain to read, a photo can be helpful. 

And as above, you can't post it here as it contains your MAC address that is personally identifiable information which the moderators are obligated to remove.

That’s a tricky question and really depends upon the honesty of the current owner. The warranty starts upon date of sale.

FYI, In the US the warranty is transferable. However, in the UK things may be different.

Here are some scenarios that buyer may contend with regarding a warranty in the US:

1. Buying from Sonos direct determining that date should not be a problem

Buying from a retailer requires additional proof.

• For example Sonos records show that a product was sold to retailer on January 1st 2020 so as far as Sonos is concerned that is the date of sale which starts the warranty period.
• The product was not purchased from the retailer until June 30th 2020 (six months into the warranty).
• The product proves defective in January 31st 2021 From Sonos perspective the product is out of warranty.
• If a warranty claim is made there are two ways Sonos may approve warranty replacement,

1. Product registration date that falls within the date of sale to a retailer
2. Proof of purchase date from retailer

I run into this quite often with Apple product purchases from a 3rd party wherein I have to upload a receipt showing purchase date from the retailer. 

Point being just knowing the serial number or Sonos records showing date of sale may or may not be sufficient to determine warranty status.