Can I switch between the monthly and yearly plans?

If you are on a yearly plan, you cannot switch to a monthly plan until the end of the billing cycle. Once the yearly billing cycle is complete, you can then switch to a monthly plan if you wish. However, you can upgrade from a monthly plan to a yearly plan at any time

Remember: If you switch from a monthly to a yearly plan, the discount for the first-year subscription will only apply to a new yearly subscription and will not be applied retrospectively to your current monthly subscription. Similarly, if you switch from a yearly plan to a monthly plan, you will lose the discounted rate and will be billed at the monthly rate. It is only possible to switch from a yearly to a monthly plan when you cancel the yearly plan. All plans run until their renewal date, and cancelled plans will not renew automatically.