Learn Spanish (Latin America): ¿Desde cuándo requiere el gobierno este trámite? - Since when does the government require this paperwork?

Desde means since or from. Just like in English, we combine desde and cuándo to form ¿Desde cuándo...? (Since when...?) to ask about the starting point of an ongoing action. If you just asked ¿Cuándo requiere...?, it would mean When does it require...?, which asks for a specific or future time rather than a duration starting in the past.

Why is the subject (el gobierno) placed after the verb (requiere)?

In Spanish questions, it is very common to invert the word order, placing the verb before the subject. You could technically say ¿Desde cuándo el gobierno requiere este trámite?, but putting the verb first (¿Desde cuándo requiere el gobierno...?) sounds much more natural to native speakers.

I see requiere has an ie in it. Is requerir a stem-changing verb?

Yes! Requerir (to require) is an e to ie stem-changing verb in the present tense, just like querer (to want) or preferir (to prefer). That is why the e in the stem changes to ie for the he/she/it form, giving us el gobierno requiere.

Why is it este trámite and not esto trámite?