Avoid using if you can
Avoid using if you can, Distrokid is definitely a better service (only using Tunecore as I can't upload the ISRCs I need to Distrokid as they were created on a different DK account and they block that for some reason, the only negative comment about DK). The user interface is rubbish, in all black and gets stuck often if you don't follow the odd layout properly (which isn't easy). Every release I've made has been rejected for the most obscure comments on track length, artwork layout/text or colour and the titles of several tracks had to change just to follow their guidelines. Annoyingly all these issues were fine with Distrokid and didn't get flagged. Tunecore wouldn't release 2 tracks to Apple/iTunes due to the artwork, even though they were already on the Apple/iTunes from the previous distributer. Customer support are difficult to communicate with and depending what tier you're on, take 2-3 days to reply to basic questions. Wish I'd gone somewhere else than Tunecore, don't waste your time with them.