Edwal Rospigliosi wrote:
First of all, you need to get a taxpayer identification number - RUC (Registro Unico de Contribuyente), and register as 4th category (independent professional). For this, you need to have a valid DNI or a Foreign Resident Card.
With that, you can issue "recibos por servicios profesionales" (not invoices, but similar), and a certain percentage is retained by the company you're issuing that receipt for (10%, I believe). Those receipts must be printed by a SUNAT-authorized printing workshop.
You can get more information from the SUNAT website: http://www.sunat.gob.pe.
[Editado a las 2008-10-29 17:01]
thanks for the hint I managed to find most of the information I need on the sunat site. I just need to find out what, if any, are the "other" taxes a freelance has to pay (essalud, afp, impuesto de solidariedad, etc) beside income tax.