As a Luxe subscriber, your BoxyCharm Base box will automatically be upgraded to Luxe every March, June, September, and December. In between Luxe months, you'll receive your Base box as normal.
Depending on when you join the Luxe subscription, your first Luxe box will either replace your Base box OR ship in addition to your Base box. It's possible to receive your first Luxe box on a non-Luxe month. To learn more, check out the article: Will my first Luxe box replace my Base box or ship separately from it?