iPhone won't dial my 1-800-PHONE-NUM

Hello all 🙂

Thanks for taking the time to look at my post.

My question: Why can't I dial vanity 1-800 numbers with extra digits on my iPhone?

1-800-555-5555 works fantastic! But when you throw in an extra digit (not uncommon for 1-800 numbers) ie. 1-800-555-55556 then this number fails to dial.

The reason I ask is because I recently started a non-profit organization which uses a vanity number, 1-888-9AUTO-SPY. This number dials out fine on blackberries and other phones, but fails to dial out on my iPhone(3Gs) - and other iPhones(4) on other networks.

I find this interesting, because during my research I noticed that apple had a vanity phone number for facetime users, 1-800-FACE-TIME (also with an extra digit), how did that number manage to dial out?

I've searched high and low to find an answer to my question but failed to find one. The mobile phone companies I reached out to (Bell & Rogers/Fido Canada) couldn't supply me with it, nor could the company which supplied me with my 1-888 number, and I didn't find anything helpful online either 😟

So as a last resort, I am reaching out to you, the knowledgeable people behind the Apple discussion boards.

I really appreciate your time and effort, and hope to find answer 🙂

Thank you, sincerely.