Rebel Without a Claus by Abigail Drake

Christmas elf Tinklebelle Holly is a screwup. Demoted to a job in the reindeer division after one infraction too many, she hates her job, hates her life, and despises the North Pole.
But when a surprise visitor arrives from Elven High Council, and Tink is assigned to show him around, everything changes. Jax Grayson is a dark elf, and unlike anyone she’s ever met. Looking past his obvious hotness, Tink knows he has a secret, and the audit he’s supposedly performing doesn’t feel legit.
After an unexpected tragedy occurs, Tink’s life is thrown into even greater turmoil, and it seems like Jax might be the only one Tink can truly trust. Can she help him figure out what’s happening on the North Pole, or will Jax be her worst mistake of all?