A déclaration sur l'honneur literally translates into English as a 'declaration on one's honour' but that phrase sounds archaic in English, bringing to mind men in curly wigs fighting duels over insults to their honour.
A better translation of déclaration sur l'honneur is a 'sworn statement' or an 'affidavit' and these declarations have a legal standing in France, complete with sanctions for people who make false declarations.
Essentially this is a document that you sign stating that a certain thing is true – some official forms are déclarations sur l'honneur or attestations sur l'honneur and you can also write your own declaration in certain circumstances, in which case the document must contain your full name, address and date of birth, a statement saying that you declare a certain thing to be true and must also be signed with the date and place of signature added.
The French government has a template that you can use for a declaration HERE.
These documents are a standard part of the French legal and administrative landscape, but have become more commonplace during Covid where many everyday actions now require a déclaration sur l'honneur.
The attestation which was required to go out during lockdown (and is still required for trips out after curfew) is an example of a déclaration sur l'honneur – you are not required to provide proof that you are, for example, going to the supermarket since this would obviously be difficult to furnish, but by filling out the form and signing it (or clicking the box on the online version) you are making a sworn statement as to the purpose of your trip out.
The same applies to people entering France from a foreign country, they are required to swear that they do not have any Covid symptoms and the form states that Je soussigné déclare sur l'honneur n'avoir presenté, au cours de dèrniers 48 heures aucun des symptômes suivant – I, the undersigned declare on my honour that in the last 48 hours I have not had any of the following symptoms.
But it's not just Covid-related forms that require this declaration, you will often be asked for one by official bodies including the Pôle emploi (unemployment office), tax authorities or social security. If you are getting married or Pacsé (a civil partnership) you will be required to declare that you live together and there are no family ties between the two partners.
The declaration can also be used if you lack official documentation, for example if you don't have house deeds, a rental contract, utility bills or other official means to prove your address you can ask your landlord to make a sworn declaration that you live in the address specified.
So what happens if you are discovered to have lied on a sworn statement?
Since this is an official document, you can be prosecuted if you are discovered to have lied on a déclaration sur l'honneur or to have produced a false declaration.
If you have used the false declaration in the context of tax or social security you would usually be prosecuted for tax or benefit fraud.
If you are found to have forged someone else's signature on a déclaration sur l'honneur you can be prosecuted for forgery, which carries a maximum penalty of 3 years in prison and a €45,000 fine.
The maximum penalty for using or drawing up a false declaration is 1 year in prison and a fine of €15,000.
If the false declaration is prejudicial to another person or the public treasury (except in cases of tax fraud), the maximum penalty is 3 years' imprisonment and a fine of €45 000.