Plate Transfer Question

[Stuff]

So following the .gov page here > https://www.gov.uk/transferring-vehicle-registration-number-form-v317, I'm a little confused.

Do I need to send V5C's and MOT certificates for both cars, or just mine? I've filled in all the V317 ready to send, but it's quite confusing :/

 

[Torch [P4]]

Both cars because they need to issue new documents for both cars