Whats with iPhone requiring a 1 ?

Question

I have had a phone number in my contacts for nearly a year now on this phone. Its an 800 number. As everyone knows, cell phones don't use the "1" before area code and number anymore. That is only needed for archaic landlines. But this number has been in my phone as (800) XXX-XXXX for nearly a year. Just today out of thin air, when I dial via Contacts, it gives me a jingle and then "Were sorry, your call cannot be completed as dialed". I tried 10 times. No luck. In fact, I called another number out of state - a 619 number and an 858 number and it worked fine. No leading "1". But still the 800 suddenly was not working. So I added a 1 before it. It worked.
When you add a new contact to your phone, it also puts a 1 before it.
Whats with the iPhone requiring a 1? Why did my phone suddenly change to where I cant dial the 800 number without a 1?
Weird...

Answer 1

HLT1 wrote:
In fact, I called another number out of state - a 619 number and an 858 number and it worked fine. No leading "1". But still the 800 suddenly was not working. So I added a 1 before it. It worked.
Both those area codes are not out-of-state; they're San Diego, California. So you were calling IN-state. Maybe you meant you were calling out of your area code.