err on the side of caution

American  

[er on thuh sahyd uhv kaw-shuhn, ur] / ˈɛr ɒn ðə ˈsaɪd əv ˈkɔ ʃən, ˈɜr /

idiom

1. to reduce risk by planning or acting more carefully than might seem absolutely necessary.

   Budget for all your known expenses, but err on the side of caution by also allowing funds for unforeseen circumstances.

   Sorry, but I removed your image from the thread—it’s probably not offensive, but I always err on the side of caution with such things.

---

Etymology

Origin of err on the side of caution

First recorded in 1780–90

Example Sentences

Even if we can’t be sure something is conscious, we might err on the side of caution by assuming it is – what philosopher Jonathan Birch calls the precautionary principle for sentience.

From Science Daily • Jun. 5, 2026

He felt that a return before opening day was a bit ambitious, and that it would be better to err on the side of caution.

From Los Angeles Times • Feb. 16, 2026

"We're a week away from the Test series - always err on the side of caution," said Cummins.

From BBC • Nov. 12, 2025

Leaders’ first instinct was to err on the side of caution.

From The Wall Street Journal • Nov. 11, 2025

Knowing that the horse, when forced, tended to become obstreperous, Pollard may have decided to err on the side of caution and advise Workman to withhold the whip.

From "Seabiscuit: An American Legend" by Laura Hillenbrand