Faute de preuve, l’assureur refuse l’indemnisation.

Here, faute de is a fixed expression meaning for lack of, in the absence of, or because there is no.

So:

• Faute de preuve = for lack of evidence / because there is no proof

Even though faute often means fault in other contexts, that is not the meaning here. In this expression, it is idiomatic.

For example:

• Faute de temps, je ne viendrai pas. = For lack of time, I won’t come.
• Faute d’argent, ils ont abandonné le projet. = For lack of money, they gave up the project.

So in your sentence, faute de introduces the reason why the insurer refuses compensation.

After faute de, French usually uses the noun without an article.

So you commonly get:

• faute de preuve
• faute de temps
• faute d’argent
• faute de moyens

This structure expresses a general absence of something, not one specific item.

So faute de preuve does not mean because of one missing proof. It means because there is insufficient evidence / because evidence is lacking.

The apostrophe shows elision.

The definite article le becomes l’ before a vowel sound:

• le assureur ❌
• l’assureur ✅

This is exactly like:

• l’homme
• l’école
• l’entreprise

So l’assureur simply means the insurer.

These two words are easy to confuse:

• l’assureur = the insurer, the insurance company or the party providing insurance
• l’assuré = the insured person, the person who is covered by the insurance

So in your sentence, l’assureur refuse l’indemnisation means the company is refusing to compensate.

Because refuser can take a direct object.

So French says:

• refuser quelque chose = to refuse something
• refuser l’indemnisation = to refuse compensation / to deny compensation

You use refuser de + infinitive only when the next thing is a verb:

• Il refuse de payer. = He refuses to pay.
• L’assureur refuse d’indemniser le client. = The insurer refuses to compensate the client.

So:

• refuse l’indemnisation = refuses the compensation
• refuse d’indemniser = refuses to compensate

Both are possible, but they are built differently.

Indemnisation is a formal word often used in legal, insurance, and administrative contexts. It means compensation, payment of damages, or the process of compensating someone.

In insurance, it often refers to the insurer paying money after a loss, accident, or claim.

So:

• refuser l’indemnisation = to refuse compensation
• in insurance English, it could also be understood as to deny the claim payout

It is more formal than everyday words like payment or money back.

French often uses preuve in the singular in a general, abstract sense.

So faute de preuve means for lack of proof/evidence in general, not necessarily because one single proof is missing.

This is similar to how English often uses evidence as an uncountable noun.

If French wanted to emphasize multiple separate supporting documents or facts, it might use a different wording, such as:

• faute de preuves suffisantes = for lack of sufficient evidence
• en l’absence de preuves = in the absence of evidence/proofs

But faute de preuve is perfectly natural and idiomatic.

Because Faute de preuve is an introductory phrase placed at the beginning of the sentence.

It sets up the reason first:

• Faute de preuve, l’assureur refuse l’indemnisation.

This comma is very natural in written French, especially in formal or administrative style. It helps separate the introductory reason from the main clause.

You could also place the phrase later:

• L’assureur refuse l’indemnisation faute de preuve.

That version is also correct. The meaning stays essentially the same, though starting with Faute de preuve gives the reason slightly more emphasis.

Yes, it is quite formal and sounds legal, administrative, or insurance-related.

Several things make it formal:

• faute de is more formal than everyday alternatives
• assureur is a professional/legal term
• indemnisation is a technical administrative word

In more everyday French, someone might say something like:

• Comme il n’y a pas de preuve, l’assurance refuse de payer.
• Sans preuve, l’assureur refuse de vous indemniser.

Those versions are less formal and more conversational.

Yes, often you can, but the tone changes.

• Faute de preuve = more formal, written, legal, administrative
• Sans preuve = simpler, more direct, often more everyday

For example:

• Faute de preuve, l’assureur refuse l’indemnisation.
  Very formal, official tone.

• Sans preuve, l’assureur refuse l’indemnisation.
  Still understandable, but a bit less legal-sounding.

In official documents, faute de preuve is especially common.

Yes. A very natural alternative is:

• L’assureur refuse l’indemnisation faute de preuve.

This puts the main action first and the reason after it.

Both are correct:

• Faute de preuve, l’assureur refuse l’indemnisation.
• L’assureur refuse l’indemnisation faute de preuve.

The first version sounds a bit more formal and foregrounds the reason immediately. The second may feel slightly more straightforward.

A careful pronunciation would be roughly:

Fot de prœv, lasyrœr ʁəfyz lɛ̃demnizasjɔ̃.

A few points:

• Faute sounds roughly like fot
• preuve has the French vowel eu, which does not exist exactly in English
• l’assureur begins with l’ linked directly to the next word
• indemnisation has nasal vowels in the first syllables

A rough English-friendly approximation would be:

foht duh pruhv, lah-suu-rur ruh-fewz lan-dem-nee-zah-syon

That is only approximate, but it can help you get started.