Why are French customs opening my mail from US?

Reader question: French customs officials seem to be repeatedly opening mail sent to me from the US. Why is this happening?

There is no general reason why French customs authorities would be continually opening mail coming from the US, or mail coming to you specifically. 

Customs authorities do have the right to inspect mail from non-EU countries, and this can include physically checking that undeclared goods are not being sent, and if they are, whether they are subject to duties. 

The first thing is to be sure that authorities are in fact opening your mail. 

Is there any information stating French customs have opened your letters/parcels?

Customs officials typically reseal letters or parcels with specific tape and a sticker informing the recipient that it was opened by customs, why this was done, and any follow-up action taken.

If this is a frequent occurrence, you could contact Infos Douane Service on 0 800 94 40 40 about this.

One potential reason authorities may be opening your mail is its size. 

If you are receiving items that seem thicker and heavier than a usual letter (either because they are being sent via padded or thicker envelopes, lots of documents inside are increasing the size, etc) authorities may be opening it to ensure it does not include undeclared goods. 

If it consistently happens with mail carried by a certain service, such as La Poste, FedEx, UPS, etc, contact its customer service or go to your local post office to query this.  

Otherwise, letters and enveloped packages may suffer from damage during automated processes, particularly if they are larger than usual. This however, would not account for mail being frequently opened. 

Conversely, some Americans have experienced problems sending letters and parcels back to the US from France.