Lepton number violation and its relation to neutrino masses are investigated in several versions of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>S</mml:mi><mml:mi>U</mml:mi><mml:msub><mml:mrow><mml:mfenced separators="|"><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:mfenced></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow></mml:msub><mml:mo>⊗</mml:mo><mml:mi>S</mml:mi><mml:mi>U</mml:mi><mml:msub><mml:mrow><mml:mfenced separators="|"><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:mfenced></mml:mrow><mml:mrow><mml:mi>L</mml:mi></mml:mrow></mml:msub><mml:mo>⊗</mml:mo><mml:mi>U</mml:mi><mml:msub><mml:mrow><mml:mfenced separators="|"><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:mfenced></mml:mrow><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:math>model. Spontaneous and explicit violation and conservation of the lepton number are considered. In one of the models (the so-called economical one), the lepton number is spontaneously violated and it is found that the would be Majoron is not present because it is gauged away, providing in this way the longitudinal polarization component to a now massive gauge field.