Every place you shop at will give you a Vat refund form(they fill it out). You will only need to take all your goods(unused and in original packaging, incase the customs officer wants to see them) to the airport and get the Vat refund forms stamped at the customs counter. Once these forms have been stamped you can opt for credit card refund (fill out credit card number on the form yourself if not already done) and drop the form off in the drop boxes for the specific company (global blue or premier tax) or go to the vat refund office at the airport and get your refund in cash. Since Barcelona is your exit point from EU, that is where you get all your forms stamped, no matter where in EU you bought them. Check out the airport map for Barcelona to see where these counters are located. Also, if you plan to check these items in, you need to first get your boarding pass but not check the bag in, go to customs, get the customs stamps on your vat refund forms and then check the bag in. At the customs counter in Rome, they had a bag drop belt right there. So, no need to go back to airline counter. In Paris, we had to go back to airline counter because we used Pablo system(automated kiosk for customs)