MT5 server request limits

Causes, most likely first

1. The EA polls the server instead of reacting to ticks

Every call that reaches the server — order operations, history queries, symbol refreshes — counts. An EA that requests data on a timer rather than acting on the tick event can generate thousands of calls a day while placing almost no trades.

2. A prop firm request cap applies

FTMO caps at 2,000 server requests per day per instrument. That is generous for a strategy trading a handful of times a day and restrictive for a high-frequency one, and almost nobody explains what it means in practice: it constrains how the EA reads data, not how often it trades. Confirm the current figure on the firm's own page before relying on it. See prop firm rules.

3. Retry loops are multiplying requests

An EA that retries a rejected order in a tight loop turns one failed trade into hundreds of requests. This is the same defect that makes requotes worse, and it shows up here as throttling rather than as rejection.

4. History is being re-read on every tick

Re-querying deal or order history repeatedly is a common and expensive pattern. Cache it and refresh on change rather than on schedule.

Why this happens

Request limits are invisible until they are hit, and the symptom — orders failing after hours of normal operation — looks like a connection problem rather than a quota.

For anyone evaluating an automated system for a funded account, this is worth asking about directly. A vendor who has never considered request volume has probably never run their software under a cap.