I don't want to go into all the details but I used to work in this field dealing with people who had been ripped off by their equivalents of HMRC as well as local cartels. I used to deal with cases from all over the world. Canada, USA, Japan, Asutralia, even Africa (Ghana), EU, etc. By far the worst cases were all from Portugal. Folk that had moved back to the UK and had lost their homes because they couldn't sell them and being chased for tax bills for money they never received.
2 notable cases were;
Guy asks me for help. I ask him what is going on. He says Spanish authorities are going to take his home tomorrow and he can't get hold of a van to take his stuff away. I said well you have left it to the last minute had you called me months ago I may have been able to help you but at this point it's far too late. He's literally begging me but the fact he's left it to the day before they are going to come and evict him out his spanish villa means literally nothing I can do. I remember this case as I can still remember the fear in his voice he was begging me for help. They took his home and all his possessions the following day.
Another guy sold his property for £500K in England and moves to Portugal. He hires a lawyer there to buy some land for him. Lawyer runs away with £20K of his money. He hires another lawyer to buy some land. This lawyer buys him land for £100K but he takes a part of his land to keep as his own as well as charging him £20K for buying the land so he ends up with £75K worth of land and he paid £120K for it. Lawyer then sells that plot on to someone else and likely rips them off too.
He then commissions builders to build a property and tells them budget is £200K, he ends up going through 3 different builders as they kept ripping him off. Every time he goes to the bank to withdraw money the teller tells him as it's a large transaction and from a foreign account he has to charge a handling fee and he essentially pockets money from him every time he goes to withdraw money to pay the builders. He has a fireplace in his property. There is only one person you can buy firewood from in the village. Guess who he is? The local police officer. He essentially has a monopoly and cartel and charged 3 times the going rate to foreigners. This poor bugger ends up with cancer. Portuguese hospital refuses to treat him for it. So he has to move back to the UK. Luckily he still has a bit of money left over from his £500K but it's practically nothing at this point. He buys a small place whilst he receives treatment worth circa £180K which he managed to put a small deposit of £50K down for. He has lost over £450K during his time in Portugal. He can't sell his property over there. Eventually he gets a russian buyer but he can't get a mortgage. He agrees to provide a mortgage to him and he has to pay him monthly like he would a bank. The Ruski agrees and takes the home, he never makes his payments. Now Portuguese authorities are after tax on the sale of the property which he never got a cent for. Remember the poor bugger has cancer they refused to treat and luckily the NHS saved him.
When you move to these places first of all they have different taxation rules for foreigners especially foreigners that buy property. France as an example used to have a rule where after 15 years foreigners don't pay tax when they sell their main residence they recently adjusted that to 30 years. Also the Spanish authorities refuse to speak to you in English. All communication is in Spanish. You need to translate all their documents at your own expense. They will also only speak with you over the phone so you need to be able to speak Spanish or hire a local lawyer / tax specialist (which going back to previous example in portugal will rip you off as he knows you can't speak the lingo)
Foreigners are basically seen as bags of money to be plucked bare in both those countries not only by locals but by the police and government.
Spain for example if you owe them money and they don't have your current address. Their way of notifying you is putting your name on the official government tax website. So you nee to check this daily. Oh and as soon as your name is on the website you from that date only have 30-90 days to appeal. As you can imagine nobody knows this and months pass before they find out and boom they have zero rights to appeal as time has lapsed for the appeals process.
So can you answer my question how long did you live in both countries for and did you buy property in either country and sold it after you left?