Assure vs Ensure vs Insure: Which One Do You Need?
You assure a person, ensure an outcome, and insure against loss.
I assure you. Please ensure it is locked. The van is insured.
The test that settles it
Look at what follows the verb. A person means assure. A result means ensure. Money and risk mean insure.
“___ the doors are locked” → a result, so ensure.
“I ___ you it is safe” → a person, so assure.
Assure: to reassure a person
To tell someone something confidently so they stop worrying. It always has a person as its object.
I assure you there is no charge.
She assured the committee it was ready.
He was assured of a place.
Is there a person straight after the verb? Then assure.
Ensure: to make certain
To take steps so that something happens. Its object is a situation or a clause, never a person.
Please ensure the form is signed.
Checks ensure nothing is missed.
This will ensure a fair result.
Swap in make certain. If it works, ensure.
Insure: to cover against loss
To arrange financial protection. It belongs to insurance and nowhere else.
The house is insured for its full value.
You must insure the equipment.
They refused to insure the trip.
Is money or a policy involved? Then insure.
Side by side
| Assure | Ensure | Insure |
|---|---|---|
| Reassures a person | Makes an outcome certain | Covers a financial risk |
| Object is a person | Object is a result | Object is property or a life |
| Swaps with promise | Swaps with make certain | Swaps with cover |
| I assure you | Ensure it happens | Insure the car |
The exceptions
In the United States insure is often used where British writers would put ensure — insure that everyone is notified.
It is accepted there, but it is not the safer choice anywhere. Keeping insure for insurance means no reader can mistake you.
British insurers use assurance for policies that pay out on an event certain to happen — life assurance — and insurance for events that may not, such as fire. The distinction is fading even in the trade.
Where people get it wrong
| Incorrect | Correct | Why |
|---|---|---|
| Please assure the door is closed. | Please ensure the door is closed. | A result, not a person. |
| I want to ensure you of my support. | I want to assure you of my support. | A person follows. |
| Ensure your valuables before travelling. | Insure your valuables before travelling. | A financial policy. |
| insure that the report is accurate | ensure that the report is accurate | An outcome, in British usage. |
Practice — choose the right word, then check yourself.
- Please ___ all windows are shut.
- I can ___ you it will arrive on time.
- The jewellery is ___ for ten thousand.
- Nothing can ___ success.
- He ___ her that the money was safe.
Show the answers
1. ensure 2. assure 3. insured 4. ensure 5. assured
Frequently asked
Which is safest if I am unsure?
Ask what follows the verb. A person takes assure; anything else is almost always ensure, unless money is at stake.
Is reassure different?
It is assure again, with the sense of calming someone who is already worried.
More words people confuse
