Cancel Trello Business Class
You can downgrade your Trello Business Class team from within your Trello account. This will stop you from being billed again in the future, and will remove the option to use Business Class features in your account. Cards and boards which made use of those features (like custom backgrounds or attachments larger than 10 MB) won’t lose them, but you won’t be able to upload new backgrounds or add new large attachments.
What happens to our team after we downgrade?
When a team downgrades from Business Class, it retains its Business Class features and unlimited boards until the end of its prepaid service period. At the end of its prepaid service period, it becomes a free Trello team that can hold 10 boards.
If a team member chooses to downgrade the team, that member will see a list of the 10 most active team boards that will remain open, while any other boards will be closed but not deleted. To choose which boards are closed or kept open, extra boards can be closed prior to downgrading: https://help.trello.com/article/1177-personal-vs-team-boards#Business-Class-Enterprise-Team-Boards
Free teams can enable one Power-Up per board, and once the team has downgraded to a free status, there is a short grace period that allows the team to choose which Power-Up they would like to keep on each board. Power-Up data is not deleted when the Power-Up is disabled, and that data will be restored once a Power-Up is re-enabled on a board.
Downgrade from Trello Business Class
To downgrade from Trello Business Class, you’ll need to be a team administrator. Either navigate to your team's billing page (https://trello.com/your-team-name/billing) directly, or navigate to your own profile and click on your team's name and the Billing tab.
On the Billing tab, scroll to the bottom of the page. Click the “Cancel Business Class” link to downgrade from Business Class and prevent your card from being billed in the future.