As of November 2012, the SL are no longer tax-exempt transmissions.
If you have to pay invoices in Spain, you will be henceforth forbidden to do so in cash for payments exceeding € 2.500, when one of the two parties is a company or a professional. With this regulation, the government wants to eradicate the deeply rooted habit of paying cash without VAT – and therefore not declaring the income – of bills, such as those for craftsmen.
For property sales between private individuals they are exempted from this regulation, only when the buyer is a tax resident in another country. In this case, the cash limit is a maximum of € 15,000.
If you want to take advantage of the tax benefits for the purchase of a property there’s no tax benefit by doing so through a company (SL) any more. This legal form was once the preferred model in order to avoid paying transmission taxes. Since late October, the transmission of a company that holds a property is no longer exempt from payment of transmission taxes and therefore no longer of interest for this use.