Category: Mobile Billing · Last updated 5 Oct 2026
Why your first mobile bill may be higher than expected
Why your first mobile bill can be higher than your monthly plan fee: your plan is billed in advance, with any part-month charges and usage added.
It's common for a first mobile bill to be higher than your regular monthly plan price, and this is usually explained by a couple of one-off factors rather than an error.
Part-period and advance charges
Mobile services run on a fixed billing period from the 28th of one month to the 27th of the next, and your plan fee is charged in advance. If your service started partway through a period, your first bill includes a part-period charge from your start date to the 27th, plus your plan fee for the next full period.
One-off SIM or eSIM charges
A once-off charge applies for the SIM card or eSIM when your service is first connected. The same charge applies later if you replace a SIM, swap to an eSIM or reactivate a service.
Add-ons and usage
If you've added a smartwatch companion plan, it has its own part-period charge, advance charge and eSIM charge on its first bill. Usage outside your plan, such as automatic data top-ups, international calls or travel packs, is charged on the bill after the period you used it in.
If your first bill still looks higher than these factors would explain, contact us and we'll go through the breakdown with you.
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