What to expect with changes during first billing?

[tumblingdice03]

Hoping to get an idea of what to expect on the first bill as I added a Torch 2 weeks ago with basic smallest plan, unlimited msg with mobile to any mobile and 200 mb data for BB. I couldn't add my son then as I had to do a deposit so I plan to do his this week. Will my first bill basically be my amount pro rated for those days then the family plan kick in after the switch? So basically I'll have a slightly less bill than I would normal due to the partial time on solo plan before being able to add the 2nd? I just want to get an idea so I'm not floored when that first bill hits. Especially after coming up with 2 descent sized deposits beforehand!

[TheQ805]

you're first bill is going to have prorated charges for each plan, the amount of time it was used.
at&t also bills a month in advance, so you'll have your prorated charges plus the full monthly recurring charge for the following month.... afterwards, you'll just have your normal bill. this is assuming that all your changes have occurred within one bill cycle.

[tumblingdice03]

Wow so my first bill will basically be 2 months as it looks like my billing cycle date is 2 days prior to my start up date. Good to know as I'll be better prepared and good to know how it works. With me adding the 2nd line after 2 weeks, I was afraid it may be a large jump like giving less time available on my plans and charging overages or something like that. I still remember an Alltel nightmare from years ago where that happened causing close to a 1,000.00 bill! Although now I use hardly any normal minutes and am very thankful for the new mobile to any mobile option!