Switching plans

Assuming the charges for the old plan will be prorated, the sooner you switch, the lower your charges for the partial month be for the old plan, and in turn, the lower your total charges as well.

As long as you are staying with ATT, you can switch any time you want.  You can have the change start immediately, back date or start with Next billing.  Please be careful if you back date or start immediately that you don't reduce your plan too much.

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@barrop01 wrote:

My cycle ends on the 12th of each month. I would like to know when is the best time to switch from expensive plan to a cheaper plan.

I supposed it depends on your goal.

Cheaper bill? Making sure you have enough data for the month? Easiest to understand later?

The easiest would be to change it on-line and make it effective the start of the next billing period. That seems like it would be the most normal bill with no proration.

My recommendation is this:

If the new plan is more expensive, future date (as long as you're not going to have an overage on your current plan).

If the new plan is cheaper and willl also be enough to cover your current month's usage, back date so you get a credit that'll make your next bill lower than normal.

If they're the same price, or close enough that you don't care, you can change the plan effective today and then any unused data for the next few days would rollover into your next cycle on the 13th and you'd have extra data next month to use since AT&T doesn't prorate data and you'd have your full amount to use from today until the 12th.

It's all situation based. If you're trying to avoid an overage or already have a huge pending overage, backdate.