Idiom
by the book
Meanings
Following official rules or procedures exactly; strictly according to regulations.
Doing a job in a very strict, formal way without flexibility or shortcuts.
Definition
If you do something by the book, you follow the official rules exactly.
To do something by the book means to follow rules, procedures, or instructions exactly as they are written. It often describes work done carefully and formally, with no shortcuts. The phrase can be neutral or slightly critical, suggesting someone is strict about rules.
Examples
- Our accountant does everything by the book, even the smallest expense reports.
- The new manager insisted we handle customer complaints by the book.
- If we do this by the book, the inspection should go smoothly.
- He’s not trying to be difficult—he just follows the policy by the book.
Common mistake
Learners often say "by book" or "by the books" instead of the fixed form "by the book."
More at B2 level
- Bob's your uncle Used to say that something will be easy or will happen exactly as expected after a simple step.
- touch base To touch base means to briefly contact someone to share updates, confirm plans, or check progress.
- ballpark figure A ballpark figure is an approximate number or estimate, not an exact one.
- take the mickey To take the mickey means to mock someone or tease them in an unkind or cheeky way.
- cheap as chips Very cheap; costing very little money.
More idiom (adverbial phrase)s
- come hell or high water Used to emphasize that you will do something no matter what difficulties happen.
- in a nutshell “In a nutshell” means in a very brief and clear summary.
- out of left field Used to describe something surprising or unexpected, especially because it seems unrelated to what …
- once in a blue moon Very rarely; almost never.
- down the line At a later time in the future, often after some delay or further development.