> For the complete documentation index, see [llms.txt](https://docs.fraudcheck.co.za/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fraudcheck.co.za/product/products/verification/identity/sim-swap.md). # SIM swap check Shows whether a mobile number recently moved to a new SIM, a strong sign of account-takeover risk. Shows whether a mobile number has recently been moved to a new SIM card. A recent swap is a strong sign of account-takeover fraud, where an attacker persuades a mobile operator to port a victim's number so they can intercept SMS one-time passwords. Use it to surface that risk before authorising sensitive actions. ## How it works The mobile number is checked against mobile network operator records for a recent SIM swap. The result is passed through as the operator data source reports it. ## What it returns The mobile number checked, a SIM swap result describing whether and roughly when the SIM was swapped (for example, *Sim has been swapped within the last 6 month(s)*), and a risk flag (for example, *Sim Swapped*). If the source holds no record for the number, the result says so. ## Inputs required The person's 13-digit South African ID number, first name, last name and mobile number (local or international format). ## Data source Mobile network operator (telecom) records. ## Consent and permissible purpose You must obtain the data subject's consent before running this check, and confirm on each request that you have it. You keep the proof of consent; Fraudcheck records that you confirmed it. See [Consent and permissible use](/product/overview/how-it-works/consent.md). ## Channels Portal and API. For request and response detail, see the [API reference](https://developer.fraudcheck.co.za/consumer-service/identity/sim-swap-check). ## Outcomes The check does not return a normalised risk rating. Read the SIM swap result and risk flag text, and set your own rule for how recent a swap must be before you step up authentication or refer the person for review. ## Turnaround Near real-time, typically under 5 seconds. ## When to use it Before sending an SMS OTP, stepping up authentication on high-value transactions when a number was recently swapped, flagging accounts with frequent SIM changes for fraud review, or supporting account recovery decisions. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.fraudcheck.co.za/product/products/verification/identity/sim-swap.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.