Usage Limits
Usage Limits let you cap mobile Data and SMS usage per SIM. When a SIM reaches the set limit, the SIM is automatically disabled and a notification email is sent.
Usage Limits
Usage Limits let you set a data and SMS cap per SIM card. When usage exceeds your configured limit, the SIM is automatically disabled and a notification is sent to the technical contact on the account. Combined with the optional monthly auto-reset, this gives you hands-off cost control for your entire fleet.
You can find Usage Limits on the detail page of each SIM card in the Simbase dashboard.
How It Works
Usage Limits are checked against incoming Call Detail Records (CDRs) from the network. Each time Simbase processes a new CDR, it compares the SIM's cumulative usage for the current calendar month against your configured cap.
The sequence is as follows:
Usage accumulates as CDRs arrive from the network throughout the month.
Cap exceeded -> a CDR pushes total usage past your limit.
SIM disabled automatically. An email notification is sent to the technical contact on the account.
Important: Data limits can be exceeded
Data usage is measured and enforced based on data sessions (CDRs), not continuously in real time. Because of this, a SIM can go over the configured data limit before it is disabled.
Why overshoot happens
A SIM is disabled after a data session closes, once the final usage for that session is reported.
Example:
Data limit: 1 GB (1000 MB)
Current usage: 900 MB (100 MB remaining)
The device starts a new data session and uses 150 MB
When the session ends and the CDR is processed, the platform detects the limit has been exceeded and disables the SIM
Result: the SIM may end up ~50 MB over the configured 1 GB limit
What to expect
The SIM is disabled as soon as the system receives the session usage records confirming the limit has been met/exceeded.
The amount of overshoot depends on how the device uses data (session size and frequency).
Recommendation: If you need a strict “hard stop,” consider setting the limit slightly below your absolute maximum to account for potential overshoot.
When are CDRs generated?
Network operators create a CDR when:
A data session closes, or the SIM roams to a different operator
A fixed interval elapses (typically every 6 hours, though this varies by operator)
An SMS is sent
Simbase processes each CDR as it arrives and evaluates it against the active limit rules. There is no guaranteed maximum delay between actual usage and CDR arrival; it depends on the upstream operator.
Setting up usage limits
Log in to your account at dashboard.simbase.com and navigate to the SIM card you want to configure.
Open the Usage Limits tab on the SIM detail page.
Configure one or both limits:
Data Limit -- set the maximum data usage in GB. The SIM will be disabled when usage exceeds this value.
SMS Limit -- set the maximum number of SMS messages. The SIM will be disabled when the count exceeds this value.
Optionally enable Monthly Auto-Reset to have the SIM automatically re-enabled on the 1st of each month.
Both limits are independent. If you set both a data and an SMS limit, the SIM will be disabled as soon as either limit is exceeded.
Monthly Auto-Reset
When enabled, the auto-reset function will automatically re-enable a SIM that was disabled by a usage limit on the 1st of each calendar month. This allows your devices to resume connectivity without manual intervention.
If you do not enable auto-reset, the SIM will remain disabled until you manually re-enable it via the dashboard or API.
Re-enabling a SIM Mid-Month
You can re-enable a disabled SIM at any time via the dashboard or API. However, be aware that if the SIM's usage already exceeds the configured limit, it will be disabled again as soon as the next CDR arrives. To keep the SIM active, raise the limit before re-enabling it.
Important Considerations
Overshoot is expected. Because CDRs are not generated in real time, the SIM's actual usage when it is disabled will often be somewhat higher than the configured limit. The amount of overshoot depends on the data session size and the CDR generation interval of the network operator. Usage Limits are a best-effort mechanism, not a guaranteed hard cap.
Limits are per SIM, per calendar month. Each limit applies to an individual SIM card and resets at the beginning of the calendar month, aligned with the billing cycle.
Notifications. When a limit is exceeded, an email is sent to the technical contact on the account. Make sure your contact details are up to date under Settings.
No rights can be derived from Usage Limits. Simbase provides this feature as a tool to help manage usage, but because it depends on CDR delivery from third-party network operators, Simbase cannot guarantee that a SIM will be disabled at or below the exact limit value. You remain responsible for any usage incurred.
Frequently Asked Questions
What happens if I set both a data limit and an SMS limit?
The limits operate independently. The SIM will be disabled as soon as either threshold is exceeded, whichever comes first.
Can I apply limits to multiple SIMs at once?
Usage Limits are currently configured per SIM card from the SIM detail page. If you need to apply limits across a large fleet, you can use the Simbase API to automate the configuration.
How does this relate to the Auto-Disable function?
These are two separate features. The Auto-Disable function is available for high-usage (Green profile) SIM cards and prevents the bundle from automatically renewing when a new month starts. Usage Limits, on the other hand, monitor actual data and SMS consumption during the month and disable the SIM when a threshold is exceeded. The two features serve different purposes and operate independently.
My SIM was disabled but usage is higher than my limit. Is that a bug?
No. This is expected behavior. The limit is triggered when a CDR causes the running total to exceed the cap. Since CDRs can cover several hours of usage at once, the recorded total at the moment of disabling may be higher than the threshold you configured.
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