# Interactive Brokers API error 100: max message rate exceeded Independent and unofficial. Not affiliated with or endorsed by any broker or platform named here. Educational only: nothing here is advice, and nothing here recommends a broker or a trade. This is the markdown version of https://openbrokerapi.com/errors/ibkr/100-max-message-rate-exceeded, written from the same records as that page. Risk warning: CFDs and spread bets are complex instruments and come with a high risk of losing money rapidly due to leverage. You can lose money on these products, and each provider publishes its own loss figure under FCA rules. You should consider whether you understand how they work and whether you can afford to take the high risk of losing your money. Automated and API trading can amplify losses through bugs, connectivity failures and runaway orders. The error, as text you can copy: ``` 100 ``` - Kind: TWS API message code - Where you meet it: In the TWS API, not in the Web API and not in an HTTP status - API: [Interactive Brokers](https://openbrokerapi.com/brokers/ibkr) - Status: verified. Source: [interactivebrokers.github.io](https://interactivebrokers.github.io/tws-api/message_codes.html), checked 2026-09-19. ## What does 100 (max message rate exceeded) mean on the Interactive Brokers API? Max rate of messages per second has been exceeded. Your client sent more than 50 messages per second to TWS or IB Gateway; disconnection is likely. ## How do I fix 100 (max message rate exceeded)? Throttle outgoing requests to stay under 50 messages per second. ## Interactive Brokers limits behind this error This is a rate or allowance error, so these are the limits recorded for Interactive Brokers, each with its scope and source. Pace your requests against them. - Global requests a second (Web API): 10 requests per second - Scope: Per authenticated username, that is per Web API session - Status: verified. Source: [ibkrcampus.com](https://www.ibkrcampus.com/campus/ibkr-api-page/webapi-doc/), checked 2026-10-12. - Corroborated by [interactivebrokers.com/docs/web-api/trading/usage-and-availability/pacing-limitations](https://www.interactivebrokers.com/docs/web-api/trading/usage-and-availability/pacing-limitations) - Note: Client Portal Web API. Some endpoints carry their own lower limit, held in separate records. A breach returns HTTP 429, and both IBKR pages read on 12 Oct 2026 give a penalty box of 10 minutes for a violating IP address. - Historical market data requests: Either 10 req/s or 50 req/minute, as the page words it - Scope: GET /iserver/marketdata/history only - Status: verified. Source: [interactivebrokers.com](https://www.interactivebrokers.com/docs/web-api/trading/usage-and-availability/pacing-limitations), checked 2026-10-12. - Corroborated by [ibkrcampus.com/campus/ibkr-api-page/webapi-doc/](https://www.ibkrcampus.com/campus/ibkr-api-page/webapi-doc/) - Note: The page gives two figures joined by or and does not say which applies when, so no single number is recorded. The IBKR Campus page also lists 5 concurrent requests for this endpoint. - Market data snapshot requests a second: 10 requests per second - Scope: GET /iserver/marketdata/snapshot only - Status: verified. Source: [interactivebrokers.com](https://www.interactivebrokers.com/docs/web-api/trading/usage-and-availability/pacing-limitations), checked 2026-10-12. - Corroborated by [ibkrcampus.com/campus/ibkr-api-page/webapi-doc/](https://www.ibkrcampus.com/campus/ibkr-api-page/webapi-doc/) - Order and trade list requests: 1 req/5 s - Scope: GET /iserver/orders and GET /iserver/trades, each counted on its own - Status: verified. Source: [interactivebrokers.com](https://www.interactivebrokers.com/docs/web-api/trading/usage-and-availability/pacing-limitations), checked 2026-10-12. - Corroborated by [ibkrcampus.com/campus/ibkr-api-page/webapi-doc/](https://www.ibkrcampus.com/campus/ibkr-api-page/webapi-doc/) - Note: The same figure applies to /iserver/account/pnl/partitioned, /portfolio/accounts and /portfolio/subaccounts. The window is 5 seconds, which a single unit cannot state, so the figure stays as wording. - Session validation requests a minute: 1 requests per minute - Scope: GET /sso/validate only - Status: verified. Source: [interactivebrokers.com](https://www.interactivebrokers.com/docs/web-api/trading/usage-and-availability/pacing-limitations), checked 2026-10-12. - Corroborated by [ibkrcampus.com/campus/ibkr-api-page/webapi-doc/](https://www.ibkrcampus.com/campus/ibkr-api-page/webapi-doc/) - Session keep alive requests a second: 1 requests per second - Scope: GET /tickle only - Status: verified. Source: [interactivebrokers.com](https://www.interactivebrokers.com/docs/web-api/trading/usage-and-availability/pacing-limitations), checked 2026-10-12. - Corroborated by [ibkrcampus.com/campus/ibkr-api-page/webapi-doc/](https://www.ibkrcampus.com/campus/ibkr-api-page/webapi-doc/) ## More on the Interactive Brokers API - [All Interactive Brokers API error codes](https://openbrokerapi.com/errors/ibkr) - [Interactive Brokers API quickstart](https://openbrokerapi.com/brokers/ibkr/quickstart): From credentials to a first call on a demo account, step by step. - [Interactive Brokers API error codes](https://openbrokerapi.com/errors/ibkr): 511 decoded, each with what it means, and the fix where the source gives one. - [Interactive Brokers API endpoints](https://openbrokerapi.com/brokers/ibkr/endpoints): 23 documented, each with its method, path, parameters and source. - [Interactive Brokers API page](https://openbrokerapi.com/brokers/ibkr): The full record: access, authentication, limits and the source for each. - [Get your Interactive Brokers trade history into a spreadsheet](https://openbrokerapi.com/guides/ibkr-trade-history): Guide - [IBKR API without TWS: headless IB Gateway options](https://openbrokerapi.com/guides/ibkr-headless-gateway): Guide - [The three Interactive Brokers REST front doors compared](https://openbrokerapi.com/guides/ibkr-rest-front-doors): Guide - [Interactive Brokers MCP servers, compared](https://openbrokerapi.com/guides/interactive-brokers-mcp-servers): Guide ## Licence and how to cite The records behind this page are all rights reserved. This file is the page itself, at its own address, in another format. It is not part of the CC BY 4.0 downloads listed at https://openbrokerapi.com/data. Quote from it with a link to the page. Cite as: Interactive Brokers API error 100: max message rate exceeded. Broker API Hub, https://openbrokerapi.com/errors/ibkr/100-max-message-rate-exceeded, newest check 2026-09-19. Where you rely on a single figure, cite the source and the checked date printed beside it as well. Where this page and a broker's own documentation differ, the documentation wins.