Le client relève l’index de consommation.

Here relève is the third-person singular present tense of relever.

In this sentence, relever means something like:

• to read
• to note down
• to record

So it is not the basic idea of lifting something, even though relever can have that meaning in other contexts.

In utility or technical contexts, relever un index often means to take a meter reading or to record the current reading.

Because this sentence uses a conjugated verb, not the infinitive.

• relever = to record / to note down
• il/elle/on relève = he/she/one records
• le client relève = the customer records

So:

• Le client relève... = The customer records...
• Le client relever... would be ungrammatical here, because after the subject le client, you need a conjugated verb.

That accent is part of the correct spelling of this verb form.

The infinitive is relever, but in some conjugated forms the e changes to è:

• je relève
• tu relèves
• il/elle relève

This happens because of French pronunciation patterns in certain verb forms. The accent helps show that the vowel is pronounced more openly.

So relève is just the normal present-tense form of relever.

Because index begins with a vowel sound, and in French le becomes l’ before a vowel or silent h.

So:

• le client
• l’index

This is called elision.

A few similar examples:

• l’homme instead of le homme
• l’école instead of le école

Not exactly.

In French, index can mean an indicator, a figure, or a meter reading, depending on context. In utility contexts, l’index de consommation usually refers to the consumption reading shown on a meter.

So this is not the usual English index as in the back of a book.

It is a good example of a word that looks familiar but is used differently in context.

De consommation describes what kind of index it is.

Literally, it means of consumption. In more natural English, that becomes something like:

• consumption reading
• usage reading
• meter reading for consumption

French often uses noun + de + noun where English might prefer a compound noun or adjective.

So:

• l’index de consommation = the consumption index/reading

Because after index de, French often uses de + noun without an article when the second noun is giving a type or category.

Here consommation is not being presented as a specific separate thing; it is defining the kind of index.

Compare:

• un ticket de caisse = a receipt
• une salle de bain = a bathroom
• un relevé de compte = a bank statement

So index de consommation works like a fixed noun phrase: consumption index/reading.

Le client is the masculine singular form.

If the customer is specifically female, you would normally say:

• la cliente

So:

• Le client relève l’index de consommation.
• La cliente relève l’index de consommation.

In some business contexts, the masculine form may sometimes be used generically, but if you know the customer is a woman, la cliente is the natural choice.

Because the basic French word order here is the standard:

• subject + verb + object

So:

• Le client = subject
• relève = verb
• l’index de consommation = direct object

This is very similar to English word order, which makes the sentence structure fairly straightforward for English speakers.

A careful pronunciation would be roughly:

Le client relève l’index de consommation
/ lə klijɑ̃ ʁəlɛv lɛ̃dɛks də kɔ̃sɔmasjɔ̃ /

A few useful notes:

• client sounds roughly like klee-ahn
• relève has the open è sound
• index is usually pronounced with the final x audible in this word
• consommation ends with a nasal sound: -syon with nasalization before it

Depending on accent and speed, the unstressed e sounds may weaken or disappear.

Yes, very much.

In everyday French, especially in utilities, administration, and technical contexts, relever is commonly used for taking down information such as readings, figures, or data.

You may also see related nouns such as:

• un relevé = a statement, report, or reading
• le relevé du compteur = the meter reading
• faire un relevé = to take a reading / make a record

So this sentence uses very typical formal or technical French.

Yes. Depending on context, French might also use related expressions such as:

• Le client note l’index de consommation.
• Le client relève le compteur.
• Le client effectue un relevé de consommation.

These are slightly different in tone:

• note = note down
• relève le compteur = takes the meter reading
• effectue un relevé = more formal/technical

Your original sentence is perfectly natural in a utility or administrative context.