Saludos!

I would like to purchase AVE tickets from Madrid to Cordoba on to Seville the next day, then directly back to Madrid from Seville about a week later. Trouble is, the RENFE site wants me to be a registered user. Okay, but it keeps telling me there is an error in the NIF number. Does anyone have a solution to this or a different way to obtain these tickets in advance?

Gracias,

Admiral44 de la flota que sundio.