To remove an account, you must remove the connection to the provider. Removing a connection will remove all accounts, transactions and categories from the accounts linked to that connection.
Only remove a connection if you are certain you do not want to access the account data anymore.
You can remove a connection by heading to Connections, selecting the connection you wish to remove and then selecting Remove connection.
If you want to keep the historical data within the app but not the account, you can either hide or archive the account.
For more information, check out our article Archive or hide an account.