mrsbee, It was common practice before 2010 to have the agreed purchase price of a property and a different lower price that was declared to the tax authority. Basically it was a way for the seller to minimise capital gain and the purchaser to minimise tax payment. Commonly known as black and white payments and would be agreed by both seller and buyer normally 70% white (declared for tax) and 30% black (undeclared). All a bit of a farce as it all took place in the Notary office and was basically systematic tax evasion that was regarded as fair game at the time.
Unfortunately all this was knocked on the head with a clampdown that meant the full purchase price had to be declared on completion. This left many who purchased in good faith being stuck with part of the original sellers capital gain.
eg, Apartment bought for €300,000 under the 70/30 agreement would see the sale price to the tax authority as €210,000 and if the new owner subsequently sold for the same price he purchased it for after the clampdown then he would be liable for a capital gain of €90,000.
It was a corrupt system that was condoned by estate agents, solicitors and even the Notary and many have suffered as a result.
I would think you have been caught in the aftermath and have been assessed as not complying with the new rules by not declaring the true value of your property. (I’m not suggesting you did anything wrong).
Normally owners don’t find out till they sell so your case seems a little unusual. Sadly they can’t chase the person who sold the property to you so they have opted for the next best thing.
Hope you get it sorted.
ps. There are are certain allowable costs that can minimise your capital gains so above is just a simple illustration.