MT5 error codes: every trade retcode explained

Causes, most likely first

1. Error 10016 — invalid stops

The stop loss or take profit is too close to the current price, on the wrong side of it, or violates the symbol stops level. The most common rejection for EAs on gold. Full diagnosis: invalid stops.

2. Error 10019 — not enough money

The margin required for the requested volume exceeds free margin. Usually a lot size problem rather than a balance problem. See not enough money.

3. Error 10014 — invalid volume

The lot size is below the minimum, above the maximum, or not a multiple of the volume step. See invalid volume.

4. Errors 10026 and 10027 — autotrading disabled by server / by client

Client means a setting on your machine, fixed in one click; server means the broker has blocked it. See AutoTrading disabled.

5. Error 10030 — unsupported filling mode

The order requested a fill policy the symbol does not allow — typical when an EA moves brokers. See unsupported filling mode.

6. Errors 10004, 10015, 10020, 10021 — price problems

Requote, invalid price, price changed, off quotes: the price moved between decision and execution, or no quote was available. See requotes and invalid price.

The full retcode table

Take the whole thing as data

All three tables on this page are published as an open dataset under CC BY 4.0, with a permanent identifier: DOI 10.5281/zenodo.22296252. CSV and JSON, also mirrored on Hugging Face. If you are building tooling that has to turn a retcode into a human explanation, take the file rather than scraping this page — it is generated from the same source, so it cannot drift from what you see here.

MQL runtime errors are a different list

If you read the failure from inside the expert advisor with _LastError or GetLastError(), you get a number from a different table: the MQL5 runtime errors in the 4000s, not the server retcodes above. The two are easy to confuse because both describe the same failed order. The runtime code says *that* the trade call failed; the retcode in MqlTradeResult says *why*. Log the retcode.

MetaTrader 4 error numbers and their MT5 equivalents

Most forum answers still quote MT4 error numbers, and most of the people searching for them are now on MT5. The conditions did not change when the platform did; only the numbers did. This is the mapping.

Why this happens

Two code families look alike and are not. Codes in the 10000s are trade server retcodes — the server answering a specific order request, listed above. Codes in the 4000s are MQL5 runtime errors from inside the EA itself. A retcode appears in the Journal tab attached to the rejected order; runtime errors appear in the Experts tab.

10008 and 10009 are in the table because people look them up as if they were failures. They are the success codes.

The FIFO and hedging codes at the bottom — 10045 and 10046 — only appear on netting or US-regulated accounts, which is why an EA can run for years on an offshore broker and produce them on its first day on a US one. See FIFO and netting rules.