Why does MT4 say 'invalid stops' when I enter a signal's stop-loss or take-profit?

In this guide

The common causes
How to check your broker's limit
Related

MT4 says "invalid stops" (Error 130) when the stop-loss or take-profit you entered breaks a rule on your broker's server. The usual causes are a level too close to the current price, a stop on the wrong side of the entry, or a price that moved after you copied the signal. Check those three first, and most errors disappear.

The common causes

1. Stop is too close to the market price

Most brokers set a minimum distance, called the stop level, between the current price and any stop or limit order. If your stop-loss sits inside that distance, the order is rejected. This hits scalping-style signals hardest, and it gets worse when spreads widen around news.

2. Stop is on the wrong side

Buy: stop-loss goes below the entry, take-profit above.
Sell: stop-loss goes above the entry, take-profit below.

A swapped level is an easy typo when you're entering several trades by hand.

3. Bid/ask confusion

Buys close at the bid price, and sells close at the ask. A signal's levels may be quoted from another broker's feed, so the distance you actually have is a little different from what the signal implies, by roughly the spread.

4. Price moved before you entered

If the market ran past the signal's entry, your stop may now sit too close, or on the wrong side of the current price. Don't force the trade. Skipping it is a valid decision, and chasing usually worsens your risk-to-reward. See Forex Signal Execution Mistakes.

5. Wrong decimal places

Brokers quote 5 digits on most pairs (3 on JPY pairs). Leaving out a digit or shifting a decimal point gives you a level far from where you meant it to be.

6. Pending orders and market execution

Some brokers using market execution reject stops attached to the initial order. In that case, open the trade without stops, then modify it to add them. Do this quickly, because the trade is unprotected until you do.

How to check your broker's limit

Right-click the symbol in Market Watch and choose Specification.
Look for Stops level, shown in points.
Keep your stops at least that far from the current price.

Stop levels vary between brokers and account types, so confirm yours with the broker. If a broker's rules regularly get in the way of the signals you follow, that is worth weighing when you compare providers: Best Forex Brokers for Signal Trading.

Never respond to the error by dropping your stop-loss altogether. A trade with no stop carries unlimited downside risk, and no signal justifies that.