# lock in

CEFR B2 · Phrasal verb

Source: https://englishreference.com/word/lock-in
Updated: 2026-10-22

## Definition

to fix a price or an agreement so it stays the same. You use this to make sure a good deal does not change later.

For teachers: To commit to a fixed rate, price, or set of conditions to prevent future changes or volatility. The verb is transitive and allows for optional separation of the particle.

## Examples

- I want to lock in a low interest rate for my mortgage.
- Many homeowners lock in their mortgage rates for five years to ensure their monthly payments stay predictable.
- The treasurer advised the board to lock in the current exchange rates to mitigate the risks associated with the upcoming national election and potential currency devaluation.

## Pitfalls

- Not "We locked in the house at 10 PM." but "We locked up the house at 10 PM." — Learners often confuse 'lock in' (securing a rate) with 'lock up' (securing a building with a key).

## Usage notes

- It is most commonly used in the context of mortgages, energy bills, and investment strategies.
- Teaching tip: Contrast with 'float', which is used when a rate is allowed to change according to the market.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.