The street number is no longer required in an address

address.number was required in every address you send — a customer, a company, an invoice recipient — so an address that genuinely has none had to be padded with something to get past a 422: a named building, a rural road, or a line1 arriving from another system that already carries the number inside the street. It is now optional. Omit it when the address has no number, or when street already carries the address in full; street, postal_code, city and province are unchanged, and addresses you already send with a number keep working untouched.

One trap if you build the body dynamically: number is still validated when it is present, and an empty string is not a way to say "none". Omit the key — "number": "" is rejected with 422.