Do you send a proof before you print?
Yes. You get a digital print proof, and approving it is the cut-off for the printed card parts.
Once that proof is approved, printing runs from the file it shows, so read it closely before you sign it off. Check the spelling, the track listing, the credits and the barcode, and check that nothing important sits in the trim, fold or spine zone.
Audio has a separate deadline. Changes to the audio close roughly 24 hours after your job form is submitted. Have the running order and the master settled by then.
Tell your project contact the moment you spot something wrong, whichever of the two it is. Before the deadline we can usually fix it. After it, the file we hold is the one we make. Vinyl artwork templates · Can I change my artwork?