Subscription downgrade options are available in 
Settings → Billing menu.
Select "View plans" option from the billing page
No matter if you'd like to upgrade or downgrade
Select next action from following options:
Downgrade, from Business plan to Startup
Or from Enterprise plan to Business or Startup
If you proceed with downgrade, your new plan will start from the next billing cycle, and you'll keep current plan settings until the end of the cycle shown in your billing pane.
Changing billing period from Yearly to Monthly
In case you decide to change billing period from Yearly or event Quarterly plan to Monthly, no matter if you're changing the subscription or not, the adjustment made will kick in on the next billing period.
For such change, please contact us via chat button on the bottom right of your screen and we will change the billing period for you.
Example
Your subscription started on Apr 1st, 2024.
15th of Aug 2024, you've upgraded to yearly plan (same subscription plan) and your credit card has been charged for pro-rated upgrade charges, meaning that your new subscription start date became Aug 15th, 2024, while the renewal date for the yearly plan is Aug 15th, 2025.
In case you decide to return back on Monthly billing cycle between Aug 15th, 2024 and Aug 15th, 2025, adjustments will be applied on renewal date,
which is Aug 15th, 2025.
In case of any seat downgrade change, while waiting to be transferred to the monthly billing cycle, will also remain unchanged until the next renewal date (see explained in details in section below).
How removing extra seats works?
Whenever you upgrade your account, by adding extra seats, they will be included into your account immediately, at pro-rated charge (explained in detail here).
When the seat is removed from the account, on all plans and and any billing renewal terms, your seats will remain active in the iClosed account until the end of the billing cycle, since you already paid for it.
Therefore, your upcoming subscription invoice will still show full number of seats as you had after the last upgrade, until 1 hour before subscription renewal time.
iClosed system checks every account, one hour before the subscription renewal for any potentially empty seats. In case your account still remain at lower number of seats, it will adjust the invoice and total price, and charging your credit card on the file according to the exact number of seats you're using.
Here's a video on how to remove a user seat: