# retroactively

/ˌɹɛtɹoʊˈæktɪvɫi/ (US) · /ɹˌɛtɹəʊˈæktɪvli/ (UK) · CEFR C1 · Adverb

Source: https://englishreference.com/word/retroactively
Updated: 2026-05-18

## Definition

to apply a rule or change to a situation that already happened in the past. You use this when a new law or decision affects things that happened before it was made.

For teachers: to apply a law, rule, or decision to events or situations that occurred in the past. Often implies a change in status or legal standing that is effective from a date prior to the current one.

## Examples

- The new tax law applies retroactively to last year's income.
- The court ruled that the contract was invalid from the start, applying the decision retroactively to the original signing date.
- While the amendment was passed in the current fiscal year, its retroactive application means that all previous filings must be adjusted to reflect the new standards.

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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.