Expert Nigel Lewis, of FindaProperty.com. answers readers questions.

Q: Is it true that Spanish property owners could be in line for a tax windfall?

A: Yes, it's true. A ruling by the European Court of Justice found the Spanish Government guilty of unfairly taxing non-Spaniards who sell a property in Spain.

During a nine-year window, overseas vendors, including thousands of Brits, were charged a higher capital gains tax than their Spanish counterparts and this was deemed to be unfair.

The loophole was first exposed by currency exchange brokers HiFX and Spanish lawyers Costa, Alvarez, Manglano & Associates who, in 2007, started legal action against the Spanish government.

This succeeded after the tax was found to be in breach of discrimination rules as set out by the European Community Treaty, and a ruling enabled non-Spanish nationals who had sold a property in Spain between 1997 and 2006 to claim a 20 per cent tax rebate.

Up to 10,000 Brits are thought to be eligible to reclaim the tax, but so far just 520 cases have been submitted and 200 successful rulings handed down.

The average claim amount for those who paid the 35 per cent tax currently stands at £14,980.

But if you think you're eligible for rebate it's time to get moving: claiming the tax back takes three months and must be completed by October 31, 2010 – and the month of August is a holiday in Spain. Effectively, therefore, you only have until the end of this month to stake a claim.

Mark Bodega, Marketing Director of HiFX, thinks there are still thousands of Brits who sold Spanish properties in the eligible time period who still haven't come forward.

"But time is running out – once the deadline passes they will never be able to reclaim this money again," he said.

"We now urge anyone else who thinks they may have been affected by this to come forward."

Advice

What to do if you think you have been affected:

1. Seek professional specialist legal advice as it is not a simple case of filing your reclaim with the Spanish tax authorities. It is important to choose a specialist Spanish tax solicitor familiar with international tax laws and court procedures.

2. Even if you have already tried and been unsuccessful in your claim, you can now attempt to claim again as the rules have changed.

For more information and details of how to register your interest, visit www.spanishtaxrecalim.co.uk or call them on 0845 680 3849.