I wrote down someone's phone number and tried texting them, but my phone immediately said the number was invalid. I double-checked the number with the person, and they confirmed it was correct. What could cause this, and what should I try next?
3 Answers
This can sometimes be a temporary carrier or network problem, especially if the two phones use different providers. Testing another number can help determine whether the issue is on your end. If other texts work normally, the problem may be with that specific line.
Since this is your manager, the simplest option is to verify the number in person and ask them to send you a text first. That confirms the exact number and may also reveal whether their phone or carrier is having an issue.
First, try calling the number instead of texting, preferably from a different phone. It’s possible the number was written down incorrectly, the person accidentally gave you an old number, or their carrier hasn’t properly transferred it.

I’ve seen this happen when someone’s carrier had a temporary routing issue. Calling from another phone worked, and the number started working normally the next day.