Assure, Insure, Ensure: What’s The Difference?

Assure Insure Ensure

Assure, Insure, Ensure? You’d think it would be a simple matter to get it right.

Not always.

One of the silliest things I saw recently was this sentence:

It is called life assurance because it ensures your life and gives you peace of mind.

It sounds suspiciously like a promise that if you pay the premiums you’ll live forever. Whew!

Don’t get too excited. It’s just a really bad sentence. Read on.

Many people have trouble with the use of three similar words: assureinsureensure.

Assure, Insure, Ensure: how can you be sure?

Let’s look at the difference between these three words.


To assure’ is a verb that can also mean something like ‘to promise’, as in ‘I want you to know I’m as sure as I can be’, which essentially amounts to a promise.

I can assure you of one thing: this won’t happen again.

He assured her of his unfailing support.

The noun is ‘assurance’.

They prided themselves on quality assurance.

The company’s assurance made them feel much better.

This bring us back to the opening sentence.

The term ‘life assurance’, so I am informed, is used because you can be ‘assured’, for life, that your claim will be paid (as long as you pay your premiums). In other words you can be certain, for as long as you live, that someone will get the money when you die, whenever that might be. Sorry, but it can’t assure you of more years on earth.


The verb ‘to reassure’ means, literally, ‘to assure again’ or reinforce the assurance, for comfort and peace of mind (or not).

Let me reassure you; I will always be available.

The noun is ‘reassurance’.

Despite their reassurances, she remained troubled and afraid.


To insure’ is a verb that means, quite simply, ‘to make arrangements to be covered or compensated for loss’, of various kinds.  

It might involve a contract for financial compensation – i.e. an insurance policy.

His life was insured for $3 million

It could refer to other arrangements, made to deal with circumstances that might arise.

She diversified her business to insure herself against the vagaries of the market.

People tend not to have problems with this term.

The noun is ‘insurance’; the word also functions as an adjective.

They took out insurance against fire and theft.

The insurance premiums were always paid on time.

And, referring again to the opening sentence, ‘life insurance’ is different from ‘life assurance’, because the term for life insurance is defined and limited – i.e. you might take out a insurance policy for 50 years.


The verb ‘to ensure’ means ‘to make certain’.

You can ‘ensure’ something (a noun):
The protective gear ensured his safety in the extreme heat of the test chamber.

You can ‘ensure that’ something happens:
The stringent requirements ensured that all personnel were capable of completing the tasks.

Make sure

In less formal writing, and in speech,  ‘ensure’ can sound a little stilted; ‘make sure’ – or even ‘be sure’ – means exactly the same thing and is more appropriate, particularly when applied to people, rather than procedures, as in these examples:

Make sure you start planning your holiday early this year.

Be sure to tell your friends.

‘Ensure’ would sound awkward in these sentences.

There isn’t an exact noun form of ‘ensure’. The closest noun is ‘certainty’ or, in very rare (very formal) cases, ‘surety’.

Assure, Insure, Ensure … a final word

Get these words right to make sure your meaning is clear.

Just to finish, we could write that silly opening sentence like this:

We call it life assurance because the policy promises to cover you for your whole life and makes sure you have peace of mind.

Find out more ways to Be Word Wise.

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