il aurait fallu

it should have been necessary

→ il
phrase Rare #37,544
it should have been necessary An impersonal conditional perfect form of il faut, commonly used to express that something should have been done or was necessary in the past. It can be followed by an infinitive or by que plus the subjunctive.
FR: Il aurait fallu réserver une table avant.
EN: We should have reserved a table beforehand.

Mais avec qui il aurait fallu que je couche pour avoir une job comme ça?

But who would I have had to sleep with to get a job like that?

— Les Invasions barbares (2003)

Il aurait fallu que je te remarque, mais oui.

I should have noticed you, but yes.

— Douleur et gloire (2019)

Il aurait fallu venir hier!

We should have come yesterday!

— La dolce vita (1960)

Il aurait fallu intervenir avant.

We should have intervened earlier.

— Amours chiennes (2000)

Et il aurait fallu combien de temps?

And how long would it have taken?

— Blade Runner 2049 (2017)

Il aurait fallu prévenir avant, pas après.

They should have warned us beforehand, not after.