IMPORT DUTY

I think your 'first glance' theory is probably as close as you're likely to come to understanding it!

It will depend on the age, where you bought it, where it was made and what it is.

21% IVA will be added but import duties will range from 0 to 17%.0% on books, for example, but still the IVA.

Goods produced outside the EU or any country without a trading agreement will vary on the country with China being 45% of the value. Buy an item made in Chine for 200 euro and you pay 42 euro IVA plus 90 euro import duty on top. 

There is also a 3% tariff on goods plus the 21% IVA. So that 200 euro item from somewhere with no "dumping" tariffs will be €249.26 euro because they add the tariff to the value and then charge the IVA on the total.

This site gives a basic idea of what the charges are. https://spainbox.com/mailboxes/duty-and-taxes-to-import-to-spain-from-outside-european-union

There must be an official customs site which tells you exactly what will be charged.

Thought as much!!!!!!!!!!!!

Most probably you forgot or ignore how to deal with (Spanish) customs. Any shipment from outside EU/EWR must be accompanied by a Customs Declaration stating "used items with no commercial value", then specifying every item with it's appr, actual value "for customs purpose only". 

Many thanks for the reply, a lot of useful info to be had from the link.  I have actually dropped them a line for specific advice.

A bit of useful advice from there highlighted that DHL are probably the worst carrier you can have due to their inconsistencies and you should specify anyone but them. More often than not you might not get a choice as they are a huge company and sellers might have a contract with them.

On car parts from America I have often noted that you get a choice of carriers, but have never done any more than tick the cheapest box.  Now I'll be a bit more attentive.

Oh yes, they don’t even drive down the main road next our house because “DHL” have determined it doesn’t exist!!. I’ve paid duty, filled lots of forms and then DHL send it back because they somehow can’t see or find a major road. Sooooo annoying

I have the same problem.  I am 500m from the A31 yet the carriers say my address does not exist or no one in.

Both lies. They just can't be bothered. 

I have even sent maps and GPS co-ordinates but I expect that is too much like rocket science.  I now use another address in town which they do seem to be able to find.

My brother has just used DHL to send his property keys from UK to a Spanish tradesperson's home address so he can check there's enough building materials (already in the property) required to renovate the property.  The Spanish Customs have now billed him an extra 29 euros import/duty tax but he can't pay it because the 'url link' can only be used by the importer leg .  So our tradesperson has now got to pay it while my brother then pay the tradesperson.  At this rate , not worth sending anything from UK to Europe , their loss as well as ours.

You are aware it works both ways? I no longer send anything to UK after my daughter was charged VAT and customs duty on an item I sent for her birthday. I now use Amazon or an internet retailer in UK if I want to send anything.