Our member Bendix from Germany has shared his experience with the Spanish post office on a trip to Spain.
http://goscf.com/t/79361Things have changed a lot over time.
Two decades ago, when visiting the main post office of a larger town in Spain, I would have a look at a display case with recent issues. Most of those main post offices had a philatelic counter. Frequently, there would be a poster depicting the issues of the previous year. On some occasions, I bought the yearbook of Spanish and Andorran issues of the previous year.
The displays of postage stamps and philatelic counters have gone. If you want the yearbook, you should order it from 'filatelía' in Madrid. The post offices no longer stock them. You may even struggle to find the stamps to affix them to your mail.
When I visit a town or village in Spain, one of the first things I do, is buy postcards to send to friends in Europe, South-America, and Asia. Spain issues stamps with face values and stamps with a tariff indication. Tariff A is for inland mail and includes Andorra. Tariff B is for European destinations not covered by tariff A. Tariff C is for the rest-of-the-world, except USA, Canada, Japan, New Zealand, and Australia. In January 2022 a D-tariff (€2.10) was introduced for mail to USA, Canada, Japan, New Zealand, and Australia. At the same time, Russia was placed in zone 'D.'
My first experience with this tariff was in February 2022, when I was in San Lorenzo de El Escorial. I had to tell the very helpful staff at the local post office about the new tariff for Russia. It took some time before they found the required stamps to affix to my postcards to Russia.

Many post offices only stock packets of five self-adhesive stamps with tariff-indicator. Judging from the lack of a barcode on the back of the backing paper, these might be taken from specially printed sheets. Some have a book or cardboard box with sheet stamps kept under lock and key. Frequently, the counter clerk will disappear for a few minutes to search for that book or box.
Nowadays, I stock the tariff stamps. They remain valid after an increase in postal rates. If I have any left, I can use them on my next trip to Spain. I bought a considerable number of € 2.10 stamps in June, at the post office in Huelva. I ran out of these stamps in November. Because there was a chance of the tariffs being raised in January 2023 - that did not happen -, I visited a few post offices asking for D-tariff stamps. The post offices did not have them. Since it is difficult to find low-value stamps to make up any difference in new and old tariffs, I decided to buy only the necessary number of stamps.

So, last Friday (27 January 2022), I had to go to the post office in Castelló de la Plana to buy some stamps for the D-tariff. The counter clerk, one of her colleagues, and a man who appeared to be the senior clerk were very obliging.
The counter clerk and her colleague, however, were not aware there existed a D-tariff. The clerk and the senior clerk looked for these stamps, but they did not have them. According to the counter clerk, the computer did not even allow to order them from the supplies department. She suggested I returned the next day with the written postcards, so she could affix computer labels. She considered selling me A-tariff stamps. At € 0.78 each, I would need to buy three stamps for a total amount of € 2,34 to cover the € 2.10 postage to Russia. But she did not want me to overpay.
Together with the senior clerk, she went on the hunt for stamps that, combined, would cover the € 2.10 postage. They did find € 1 stamps. These were the 2020 LGTBI Pride Day stamps.

It would be funny to put those on a postcard to Russia. But the senior clerk and I considered the Russian bigots might throw the card in the dustbin or cause my correspondents troubles for propagating homosexuality. Since they had no € 0.10 stamps, it would not have helped much.
I considered coming back for the horrible computer-generated labels that tend to obscure part of the message. When I asked until what time they would open, the senior clerk realised it would be Saturday. The post office does not open on Saturday.
So, I ended up buying the required number of stamps times three of the A-tariff stamp.

(not a very good picture)
Next, I decided to stock up on B- and C-tariff stamps. I asked for ten each of the stamps. They had exactly ten examples of the 'Solidarity with Ukraine' C-tariff stamps issued 30 May 2022.


(the barcode they scan, so the computer can track the remaining stock)
Well, that was the reality. The computer, however, said "no!" According to the bits and bytes, they had only nine of those stamps left. Consequently, it refused to accept the sale of ten of those stamps. The counter clerk detached one stamp and sold me the remaining nine. She detached a stamp from a sheet of another issue for the C-tariff to make up the requested number of stamps.
After about 20 minutes, not counting the time I waited for my turn, I walked out of the post office with my stamps.