# add on

CEFR B1 · Phrasal verb

Source: https://englishreference.com/word/add-on
Updated: 2026-04-24

## Definition

to include something extra to what you already have or are buying.

For teachers: to include or attach an additional element to an existing entity or total; often used in commercial or construction contexts.

## Examples

- They add on a service charge at the end of the meal.
- When you book your flight online, the airline often tries to add on extra insurance or seat selection fees.
- The developers plan to add on a new wing to the hospital to accommodate the growing number of patients in the district.

## Pitfalls

- Not "The tax was added on the price." but "The tax was added on to the price." — when 'add on' is followed by a destination or target, the preposition 'to' is required after the particle 'on'.

## Usage notes

- commonly used with costs, fees, or physical extensions to buildings.
- Teaching tip: distinguish from the noun 'add-on' (hyphenated) which refers to the extra item itself; as a verb, it is often used in the passive voice regarding taxes or fees.

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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.