Process for manufacturing a multilayer data carrier by hot lamination under pressure of a plurality of superposed layers comprising at least one external layer made of at least one thermoplastic, said multilayer data carrier presenting inscriptions, called security inscriptions (25, 35, 38), characterized in that: - at least one marking film (20, 21, 36, 37) is chosen that: ∘ is designed to be able to undergo a hot lamination under pressure, called the marking lamination, with a layer, called the layer to be marked, made of thermoplastic of said plurality of superposed layers forming the data carrier, said layer to be marked being coated with the marking film, during said marking lamination, ∘ comprises a face, called the contact face, bearing decal inscriptions (22, 34) corresponding to said security inscriptions (25, 35, 38), and that are designed to mark said layer to be marked following a marking lamination of the marking film and of said layer to be marked, said contact face and said decal inscriptions making contact with said layer to be marked, ∘ is designed to be able to be separated from said layer to be marked after a marking lamination, the security inscriptions being formed on said layer to be marked, - a marking lamination is carried out on at least one layer to be marked coated with such a marking film (20, 21, 36, 37), said decal inscriptions making contact with said layer to be marked, - then the marking film (20, 21, 36, 37) is separated from said layer to be marked, the latter presenting said security inscriptions (25, 35, 38). - at least one marking film (20, 21, 36, 37) is chosen that: ∘ is designed to be able to undergo a hot lamination under pressure, called the marking lamination, with a layer, called the layer to be marked, made of thermoplastic of said plurality of superposed layers forming the data carrier, said layer to be marked being coated with the marking film, during said marking lamination, ∘ comprises a face, called the contact face, bearing decal inscriptions (22, 34) corresponding to said security inscriptions (25, 35, 38), and that are designed to mark said layer to be marked following a marking lamination of the marking film and of said layer to be marked, said contact face and said decal inscriptions making contact with said layer to be marked, ∘ is designed to be able to be separated from said layer to be marked after a marking lamination, the security inscriptions being formed on said layer to be marked, ∘ is designed to be able to undergo a hot lamination under pressure, called the marking lamination, with a layer, called the layer to be marked, made of thermoplastic of said plurality of superposed layers forming the data carrier, said layer to be marked being coated with the marking film, during said marking lamination, ∘ comprises a face, called the contact face, bearing decal inscriptions (22, 34) corresponding to said security inscriptions (25, 35, 38), and that are designed to mark said layer to be marked following a marking lamination of the marking film and of said layer to be marked, said contact face and said decal inscriptions making contact with said layer to be marked, ∘ is designed to be able to be separated from said layer to be marked after a marking lamination, the security inscriptions being formed on said layer to be marked, - a marking lamination is carried out on at least one layer to be marked coated with such a marking film (20, 21, 36, 37), said decal inscriptions making contact with said layer to be marked, - then the marking film (20, 21, 36, 37) is separated from said layer to be marked, the latter presenting said security inscriptions (25, 35, 38).