Assign specific data amount to each phone line

No, at least not through your ATT account. Some phones do have that sort of thing in their settings.

Hello, @trammynguyen,

Thank you for reaching out. @sandblaster is correct. It isn't possible to evenly distribute data between devices.

Have a great week.

James, AT&T Community Specialist

How about an option to automatically turn off data on one of my phone line when it reach to a specific amount? My grandma loves to watch youtube but she doesn’t know how to control her data usage. I want to find a way to still let her use cellular data but just to a specific amount each month. I would appreciate for any recommendations on what I can do. 

You can turn data off on any line but it isn’t automatic. You just need to keep checking her usage and shut it off when she reaches your threshold.

Hello, @trammynguyen,

It's not possible to set limits on devices within the account. You can possibly do it with the device itself itself. Here's how to set data limits on an Android phone:

1. Go to Settings>Data Usage.
2. Toggle on Set Mobile Data Limit.
3. Follow the prompts to set data limits and to refresh on your day of choice.

Let us know if this helps.

James, AT&T Community Specialist