Why Have I Been Charged on My Unlimited SIM Plan?

If you have an unlimited SIM plan but have noticed additional charges, there are a few reasons why this may have happened. Charges can occur due to data roaming, international calls, or exceeding the fair usage policy. Below, we explain the fair usage policies for O2 and Vodafone.

O2 Fair Usage Policy (Unlimited Data - UK Usage)
While O2 offers unlimited data, there are some fair usage limits to be aware of:

  • Regular usage of 650GB per month or tethering 12+ devices may result in a plan change or excess charges.
  • You receive 2,000 minutes and texts to the EU; beyond this limit, standard charges apply.
  • EU data roaming is capped at 25GB per month. Any data usage beyond this is charged at £3.29 per GB (Ex VAT).

Vodafone Fair Usage Policy
Vodafone’s fair usage policy includes restrictions on roaming and excessive usage:

  • Roaming in the Europe Zone is intended for periodic travel only, not permanent use.
  • If you roam for more than 50% of the time over a 3-month period, you will receive a notification to moderate your usage.
  • Continued excessive roaming may lead to additional charges or service restrictions.
    Excess data usage beyond the 25GB cap is charged at 3p per MB for Business plans.

For more details, please refer to our tariff guides here.