Pace yourself To maintain efficient and consistent API performance, KeyBank enforces a rate limit of 5 transactions per second (TPS) across all APIs, except for Commercial Accounts API which allows 10 TPS.If an API request exceeds the rate limit receive an HTTP 429 (Too Many Requests) status code. When this occurs, wait at least 2 minutes before making another API call.These TPS thresholds are in place to maximize stability and performance. We understand that your consumption needs might not fit within those limits. To request an increased rate limit, contact your Technical Account Manager.