Top 5 Mistakes Expats Make When Applying for French Social Security (and How to Avoid Them)

Moving to France is exciting—but navigating French administration? Not most peoples idea of fun!

One of the first and most important steps for newcomers is registering with the French Social Security system and applying for your Carte Vitale (your French healthcare card). At France Unlocked, we help English speakers make sense of this process every day—and we’ve seen the same avoidable mistakes pop up time and time again.

If you’re about to apply, read on. Avoiding these common pitfalls could save you weeks (or even months) of stress.

1. Sending an Incomplete Dossier

One missing document can cause your entire application to be delayed or returned. Many people don’t realize that even optional-seeming items are essential in France.

✅ How to avoid it:
Double-check the full list of required documents, including:

• A valid long-stay visa or residency card

• Passport

• Proof of address (see Mistake #2 below)

• RIB (French bank details)

• Proof of residency in France (e.g. lease, tax declaration, utility bills)

• Employment contract or proof of self-employment (if applicable)

2. Providing the Wrong Type of Proof of Address

Your proof of address—called a justificatif de domicile—must meet very specific criteria. Many people try to submit mobile phone bills, Airbnb confirmations, or mail from back home, which are not accepted.

✅ How to avoid it:
Use one of the following:

• Recent (less than 3 months old) electricity, gas, or landline/internet bill

• A rental contract or taxe d’habitation notice

• A certificate of accommodation (attestation d’hébergement) plus a copy of your host’s ID and proof of their address (if you're staying with someone or your name is not on the bill or contract)

Still unsure? We can review your documents to make sure they’ll be accepted.

3. Using the Wrong Form

There are several versions of the Social Security application (including older ones still circulating online). Using the wrong one can slow things down—or result in no response at all.

✅ How to avoid it:
Download the most up-to-date version of the CERFA 15763*02 form or let France Unlocked handle it for you. We make sure you submit exactly what’s needed, in the correct format.

4. Forgetting to Sign and Date Your Forms

It sounds simple, but missing signatures are one of the top reasons applications are rejected or delayed.

✅ How to avoid it:
Before sending your dossier, check every form, cover letter, and photocopy to make sure it’s signed and dated—especially at the end of the CERFA form.

5. Not Following Up

Once your dossier is submitted, it can take weeks (or months) to hear back. Some offices respond quickly; others don’t respond at all unless you follow up.

✅ How to avoid it:
Keep a record of what you sent and when. If you don’t hear anything after 6–8 weeks, it’s completely acceptable (and often necessary) to follow up by phone, email, or in writing.

If you’re using France Unlocked’s Advanced package, we’ll do that part for you.

Final Tip: Don’t Go It Alone

Applying for Social Security in France isn’t always straightforward—but it’s absolutely doable, especially with the right support. At France Unlocked, we help you prepare a complete, accurate application that’s ready to be processed. No guesswork, no wasted time..

Contact us today!