The best place to start when looking into billed events is the Usage page in the Plaid Dashboard: https://dashboard.plaid.com/activity/usage. If you have multiple products enabled, we recommend navigating through all the product tabs to get a better sense of your Items that are incurring charges.
Next, we suggest investigating your Plaid integration to see which products you are using to initialize Link, and discontinue the creation of any new Link sessions with products you no longer intend to use. This will stop charges for Plaid products using a non-subscription pricing model.
For Items that are created with products that follow our subscription fee model, such as Transactions, Liabilities, and Investments -- you will incur a continuous monthly subscription fee for each Item as long as the Item exists. This subscription is based on calendar months in the UTC time zone, and each month begins a new cycle. It's important to note that fees for Items created or removed in the middle of the month are not pro-rated.
Once you've linked Transactions, Liabilities, and Investments to an Item, Plaid will continue to pull and make available to you the refreshed data for that Item, which means that you will continue to be billed monthly for those Items until they are removed.
To stop monthly subscription fees for these Items, you can leverage the /item/remove endpoint. Removing the Item effectively ends the subscription associated with it and discontinues the monthly charges.
If you need a list of access_tokens associated with your client_id to cross-reference the Items you want to remove and ensure that everything is accounted for, please file a Support ticket.
To learn more about Plaid's Billing structure, you can visit Plaid's article 'How much does Plaid cost, and what are the pricing models?'