It is possible that after you have bought a property in Spain, you will receive a letter from the tax authorities. They will ask for more money, in concept of transfer tax (Impuesto sobre Transmisiones Patrimoniales). The reason is that they consider the price of the property stated in the deed to be lower than the market value. This letter can be sent up to 4 years after you bought the property.
If you are one of the owners receiving this kind of letter, be informed the you can simply pay OR show you opposition to the new valuation assessed by the authorities. If you oppose, you most likely avoid the payment.
We have been giving legal assistance to owners receiving these types of claims for years. Most of our claims have been accepted. Please, contact us as soon as you receive the first letter, and take note of the date of reception. We can help you.