Number portability

Portability ensures that a subscriber keeps their number when changing providers. Great for competition, it nonetheless carries a technical consequence that is often forgotten.

Since a number may have migrated from one network to another several times, its prefix no longer betrays the operator that manages it today. That's why an SMS-sending service never asks for the recipient's operator: an 06 or 07 number is enough for the routing to resolve itself, which makes sending as simple as possible.