order {id} is invalid. Price ({price}) breaks minimum tick size rule: {tick}
The order price doesn't align with the market's tick size. Use `GET /tick-size` to check the valid tick size.
The price isn't on the market's tick grid. Tick size differs by market and can change while a market runs, so fetch it with GET /tick-size and round to it. The CLOB market channel sends a tick_size_change event when it moves.
Retry? Don't retry
Sending the same request again returns the same error. Change the request first.
Any authenticated CLOB endpoint can return this.
Handling it in code
The CLOB API returns errors as {"error": "..."}. It also rewrites status codes by message, so branch on the text: anything containing "not found" becomes 404 and anything containing "unauthorized" becomes 401.
r = session.post(url, json=payload, headers=headers)
if r.status_code >= 400:
msg = r.json().get("error", "")
if "breaks minimum tick size rule" in msg:
raise ValueError(msg) # fix the request, don't retryRelated errors
For errors Polymarket doesn't document, like "order manager not ready" or 403s from the edge, see the full error guide.
Message and status from Polymarket's error reference, synced 2026-10-04.