Otherwise, you end up paying the annual fees twice in ~ 1 year.
Here's an example before CA started to waive this fee of how brutal this could be in CA for LLC owners:
California has an annual franchise fee tax of $800. This fee is due every calendar year, not every 12 months.
Calendar Year: January - December
Every 12 Months: 12 months from Today
So this means if you were to start an LLC that was "born" or "officially created" on December 31st, 2020, you would be responsible for paying the full $800 franchise tax fee for the year of 2020!
Fast forward to January 1st, 2022, one year and one day later, even though essentially only one year has passed by, instead of owing $800 to the state of California... you would owe $1600!
To make things worse, the first annual franchise tax fee payment is due within the first 3-4 months from when your LLC is formed, and from then on, due by April 15th each year. So if you were to create a California LLC that went in to existence on December 31st, 2020, you would have to pay $1600 in the first 5 months!