Sorted tracks your usage and keeps you updated when you hit 50%, 85% and 100% of your planned usage.
If you reach your monthly data allowance, you can keep going with your speed limited for the rest of that month, or simply change your data plan at any time at no additional cost.
If you don’t change your data plan your access speed will be limited 256Kbps upload and download speed for the remainder of that month (at no additional cost).