The closeness is the trap
Because the languages look alike, both families assume nothing will be lost between them. It is the practical words that trip: burro is butter in Italian and a donkey in Spanish, salire means to climb while salir means to leave, and imbarazzata and embarazada are two very different states. Instructions are exactly where false friends do the damage. Writing each version separately, rather than translating, keeps "the buffet is here" from becoming a joke.
Meal structure and timing are two different systems
Italian antipasto, primo and secondo against Spanish aperitivo, entrantes and plato principal — and the Spanish dinner starts hours later than the Italian one. Guests plan flights, transfers and the rest of the evening around when they will actually eat. Explicit start and end times per event stop anyone being hungrier for longer than necessary.
Apellidos are not middle names
Spanish guests carry two surnames and treat the pair as one name; Italian guests carry one. A form or seating chart built for one convention mangles the other — the second surname reads as a middle name or a typo. Guest details are stored as entered, so names display the way each guest writes them.
Each country has more than its national language
Spanish does not cover Catalan, Galician or Basque, and Italian does not cover the regional languages many guests read at home. Assuming one national language serves everyone quietly misreads part of the list. Catalan, Galician or a regional Italian can be added as another language on the same site.
Common questions
Is translating between two such similar languages worth it?
Yes — the closeness is what creates the mistakes. A separate version per language avoids the false friends and the wrong register, and anything you leave blank falls back to another language.
How do we handle guests with two surnames?
Names are stored exactly as entered, so a Spanish pair of apellidos stays intact and an Italian single surname is not forced into a double field.
Can one schedule serve two different meal-time expectations?
Yes. Each event carries explicit start and end times in every language, so both sides follow the evening on the clock they expect.
Which language should the ceremony booklet be in?
The site does not force one. The order of the ceremony can live in several languages, each written for its own readers, and the printed decision stays yours.