i have ruled out the dash refers to only calls to other carriers because one of my friends has a tmobile cellphone but in my billing details there is a dash next to his number everytime ive called him or he has called me.  Hmm so i still dont know what the dash means on the bill. 

I assume this is in the Type column. The W means that those calls were Wi-Fi calls. I don’t know what F stands for, but on my bill those are the T-Mobile-to-T-Mobile calls. That leaves the dashes to represent landline or unknown source calls. Those could be 1-800 numbers or calls to numbers on other carriers; things like that. 

interesting. all of mine minus the one just had the -

i know there have been some on again off again issues with call logs...wonder if this is part of it?

heavenM might have some answers when she gets a chance to pop in.

It will usually have a f or w next to the call. 

to be honest im not fully sure. jumped into mine to look and they all had the - meaning no info and one that showed T-Mobile since im guessing that was when i called in to make my payment.

actually now im wondering if thats where it would end up showing you if said call was a international call etc and the - is just a normal local/U.S call?

@HeavenM

any info on what all would show up in your call history at the far right side?