slip up

make a small careless mistake

What does "slip up" mean?

To slip up means to make a careless or accidental mistake, usually a small one that happens because you weren't paying close enough attention. It suggests a momentary lapse rather than a major failure — the kind of error that someone who is normally careful might still make, especially under pressure. You might slip up by sending an email to the wrong person, forgetting a key detail in a report, or giving an incorrect figure in a meeting. The phrase carries a sense of the mistake being unintentional and often avoidable, which is part of what makes it feel slightly different from simply saying you 'made a mistake'. It's commonly used in both spoken and written English, from casual conversation to professional discussions about performance.

Examples

I slipped up and sent the report to the wrong client — it was so embarrassing.
She's slipped up a few times under pressure, but overall her performance has been excellent.
We can't afford to slip up on the details when the contract is this important.

How to use it

subject + slip up

The most common structure — 'slip up' is always intransitive and never takes a direct object.

Even the most experienced editors slip up occasionally.

slip up + on + area of mistake

Use 'on' to specify where or what the mistake involved.

He slipped up on a key figure in the financial report.

slip up + and + consequence

Often followed by 'and' plus a result clause to show what happened because of the mistake.

She slipped up and gave the client the wrong deadline.

can't afford to + slip up

Frequently used with 'can't afford to' to stress the importance of avoiding mistakes.

With the final exam tomorrow, I can't afford to slip up on any of the grammar rules.

adverb + slip up / slip up + adverb

Adverbs like 'badly', 'really', or 'once' can come before or after the verb to add emphasis.

He only slipped up once during the entire negotiation, but it cost the team valuable time.

Common Collocations

slip up at workslip up on the detailscan't afford to slip upslip up and miss a deadlineslip up under pressurebadly slip up

Common Mistakes

Using 'slip up' as a transitive verb

'Slip up' is always intransitive — it never takes a direct object. You cannot slip up something; you simply slip up.

✗ I slipped up the presentation completely.

✓ I slipped up during the presentation.

Confusing 'slip up' with 'mess up'

'Mess up' can be transitive and often suggests a larger or more serious failure ('I messed up the whole project'). 'Slip up' is always intransitive and implies a smaller, more accidental lapse.

✗ I slipped up the entire project by missing every deadline.

✓ I messed up the entire project — or: I slipped up and missed one important deadline.

Confusing the idiomatic and physical senses

The physical sense of 'slip up' (losing your footing on a surface) is a different meaning. When talking about making a mistake, no slippery surface is involved — the context alone signals the idiomatic sense.

Usage

Slip up is neutral and works in both spoken and written English. The related noun 'slip-up' (hyphenated) is equally common and very useful to learn alongside the verb.

Frequently Asked Questions

Is 'slip-up' (as a noun) related to 'slip up' the verb?

Yes — 'slip-up' (hyphenated) is the noun form and it's just as common as the verb, sometimes more so. You can say 'I made a slip-up' or 'That was a costly slip-up' to describe the mistake itself. It's very useful to learn both forms together.

Can 'slip up' refer to a really serious mistake?

'Slip up' typically implies a small to medium, accidental error rather than a major failure. If the mistake is large-scale or catastrophic, native speakers are more likely to say 'mess up' or 'make a serious error'. Use 'slip up' for lapses that are careless or momentary.

Does 'slip up' only refer to things people say, like saying the wrong word?

No — 'slip up' covers any kind of careless mistake, not just spoken errors. You can slip up on figures, on a deadline, during a task, or in a process. If you want to talk specifically about something that was said accidentally, 'slip out' is the more natural choice.

Can I use 'slip up' in the future tense?

You can use 'will slip up' for a simple future prediction, but the future continuous ('will be slipping up') sounds unnatural and is best avoided. The most common tenses are the simple past, present perfect, and present simple.

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