Once I submit the request, how long does it take?

I got my unlock code the next day when I asked direct from O2.

The online form says up to a month. On the online chat thing they said up to a week. In reality a couple of days.

Mine took a couple of days when unlocking an iPhone.

Depends on the phone because they get it from the manufacturer but generally a few days.

Done it a couple of times with iPhones.

Both done in less than 48 hours using the online process.

24 – 72 hours in my experience.