rein in

control or limit something, especially spending, power, or behaviour

C1

What does "rein sth/sb in" mean?

To rein in something means to bring it back under control, especially when it has grown too large, escalated too far, or been allowed to operate without sufficient limits. The expression comes from horse-riding: pulling on the reins slows or stops a horse that has been running freely. This equestrian origin shapes how the phrase is used — the object is almost always something that has already gained momentum or exceeded acceptable boundaries, such as spending that has spiralled upward, power that has grown unchecked, or behaviour that has become problematic. You will encounter it most frequently in financial journalism, political commentary, and economic policy writing, where institutions, governments, or regulators are described as acting to restore restraint. It carries a sense of measured, deliberate control rather than sudden suppression — the focus is on gradually pulling something back within acceptable limits.

Examples

How to use it

rein in + noun object

The most common structure, used when the object is a noun phrase referring to something that has grown or escalated beyond acceptable limits.

The central bank is under pressure to rein in inflation before it becomes unmanageable.

rein + pronoun + in

When the object is a pronoun, it must go between 'rein' and 'in' — placing it after 'in' is not possible.

The board recognised that executive pay had become excessive and decided to rein it in.

be reined in

The passive form is very natural and common, particularly in formal and journalistic contexts where the thing being controlled is the main topic.

Defence expenditure has been reined in as part of a broader programme of fiscal consolidation.

attempt / effort / pressure to rein in + noun

This pattern frequently appears in news and policy writing to describe institutional or political efforts to restore control over something.

Efforts to rein in the national deficit have so far produced limited results.

need / struggle to rein in + noun

Used to express necessity or difficulty in bringing something back under control, often implying that the situation is serious.

The new administration acknowledged the need to rein in public borrowing without stifling growth.

Common Collocations

rein in spendingrein in inflationrein in costsrein in powerrein in behaviourrein in ambitions

Common Mistakes

Misspelling as 'reign in' or 'rain in'

This is one of the most frequent errors with this phrasal verb, made even by proficient writers. 'Reign' relates to a monarch's rule, and 'rain' is weather — neither is correct here. The spelling always comes from 'rein', the leather strap used to control a horse.

✗ The committee must reign in spending if it wants to balance the budget.
✓ The committee must rein in spending if it wants to balance the budget.
Pronoun placed after the particle

When the object is a pronoun, it must appear between 'rein' and 'in', not after 'in'. Placing it after the particle produces an ungrammatical sentence.

✗ His excesses were becoming embarrassing, so his colleagues tried to rein in him.
✓ His excesses were becoming embarrassing, so his colleagues tried to rein him in.
Confusing 'rein in' with 'clamp down on'

'Rein in' suggests measured restraint of something that has grown too large or run freely — it does not imply punishment or enforcement action. 'Clamp down on' is the better choice when the emphasis is on forceful action against wrongdoing or illegal activity.

✗ Authorities reined in the illegal trade by imposing heavy fines and criminal charges.
✓ Authorities clamped down on the illegal trade by imposing heavy fines and criminal charges.

Usage

This phrasal verb is formal and most common in journalism, politics, and business writing. It is rarely used in casual conversation — in everyday speech, 'cut back on' or 'control' would be more natural.

Frequently Asked Questions

Does 'rein in' always need an object — can it be used without one?

'Rein in' always requires an object; it cannot be used intransitively. You must specify what is being controlled, whether that is a noun phrase ('rein in spending') or a pronoun ('rein it in'). There is no natural short form where the object is left out entirely.

Is 'rein in' only used in writing, or can I use it in conversation?

'Rein in' is primarily a formal expression and is most at home in journalism, political analysis, and business writing. In everyday conversation, it can sound rather stiff — most native speakers would say 'cut back on', 'bring under control', or simply 'control' in casual contexts. You might hear it in educated discussion about policy or institutional matters, but it is rarely used in informal chat.

What kinds of things can be 'reined in'? Is it only used for money?

Money and finance are certainly the most common domain — spending, costs, inflation, borrowing, and debt are all typical objects. However, 'rein in' extends naturally to power, authority, ambitions, behaviour, and excesses of any kind, as long as there is a sense that the thing has grown, escalated, or been allowed to run freely. The key idea is momentum or excess that now needs to be brought back under control.

Can 'rein in' be used to describe controlling a person, not just abstract things like spending?

Yes, and this is actually quite common. You can say that advisors, colleagues, or institutions tried to rein someone in when that person has been acting excessively or overstepping boundaries — for example, 'her team struggled to rein her in as the campaign became increasingly chaotic.' The same sense of pulling back something that has exceeded its limits applies to people as well as abstract forces.

Are there any tense forms I should avoid with 'rein in'?

Most standard tenses work naturally with 'rein in', and the present simple, past simple, present perfect, and infinitive are all very common. The future perfect ('will have reined in') is grammatically possible but sounds clunky in practice, and the past perfect continuous ('had been reining in') is very unnatural. It is better to avoid both in formal writing.

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