# Setting the APN on a device > Find the APN for your ThingSIM and enter it in a router, camera or tracker, then check that data is working. Setup & troubleshooting · 1 November 2025 The APN for your ThingSIM is shown against that SIM in the ThingSIM portal. Copy that value into the device's mobile data settings, save it and test a connection. Do not borrow an APN from another provider or assume that the settings left by a previous SIM are right. An APN tells the device which mobile data connection to request. Signal bars alone do not prove that this part of the setup is correct. A device can show a mobile network while still failing to send a photograph, update a tracking platform or load a page. ## Before you open the settings Have the device manual and the correct SIM record to hand. Match the SIM you are installing to its entry in the portal before copying anything. This matters even when you have only two SIMs on the bench, particularly if one is already working elsewhere. SIMs arrive inactive. Activate the one you are installing in the portal when you are ready to test it. Billing starts on that day, per active SIM per month. Entering an APN in a device does not activate the SIM, and activating the SIM does not automatically fill in every device's settings. ## Set the APN step by step 1. Open the ThingSIM portal and select the SIM in the device. Find the APN displayed against that SIM and copy it exactly. 2. Open the device's configuration interface using its manufacturer's instructions. Look for mobile, cellular, SIM or connection settings. Menu names vary, so use the manual rather than searching for one universal label. 3. Find the APN field. If the device offers automatic and manual profiles, use the option that lets you enter the supplied value. Give the profile a recognisable local name if the interface asks for one. 4. Paste or type the APN without extra spaces. Check that you have edited the active SIM profile, especially on a router with more than one SIM slot. 5. Username and password are usually left blank. Follow the instructions supplied for your SIM and device if credentials are specifically required; do not put your portal login into these fields. 6. Save the profile and select it for mobile data. Reconnect or restart the device if its manual calls for that after a settings change. 7. Run the device's actual job. Send a camera image, request a tracker report or open a page through the router. Check the receiving system as well as the device's status screen. Keep a note of the working configuration with the device record. That gives the next person a known starting point after a reset or replacement, without needing to repeat every troubleshooting step. ## Where the setting goes On a router, the APN normally belongs in the cellular internet connection profile, not in the Wi-Fi network name or password. If you are installing one from scratch, follow [setting up a 4G router](/setting-up-a-4g-router) and test the mobile connection before adding failover rules. On a camera, look for the SIM or mobile network section of its app or configuration menu. Keep the camera's upload destination separate from the APN. Correct mobile data settings will not correct a mistyped account or destination in the camera service. On a tracker, follow the manufacturer's documented configuration method. Some devices accept settings through an app or SMS commands, but do not assume that a command for another model will work. ThingSIM supports SMS; the tracker decides which commands it understands. ## If the APN is wrong An incorrect APN can leave the device registered on a network without a working data connection. Compare the saved value with the portal, check which profile is selected, and test again. Avoid changing several unrelated settings at once, because that makes it harder to identify what fixed the problem. If the APN matches and data still fails, work through [signal but no data](/sim-signal-but-no-data). Check activation and remaining allowance before treating the problem as poor coverage. A SIM that has used its allowance pauses instead of generating overage charges. ## Choose the allowance for the device For a modest connected device or an initial setup with some room for testing, UK 4-network 250 MB is a starting point at £1.20 per active SIM per month. It covers O2, Vodafone, Three and EE, using whichever is strongest where the device is. The APN itself does not determine how much data your equipment needs. A camera uploading video or a shared router needs its own usage estimate. Check usage in the portal after representative operation and choose from 50 MB, 250 MB, 1 GB or 5 GB. For router installations, see [router failover](/sectors/router-failover); for help with the SIM record, use [help](/help) or [contact](/contact). ## Common questions ### Is my portal password the APN password? No. The APN is shown against the SIM in the portal, and username and password fields are usually blank unless your setup instructions specify otherwise. ### Does changing the APN activate my SIM? No. Activate the SIM separately in the ThingSIM portal, then save the correct APN in the device and test its data connection. ### Can I use the APN from my previous SIM? Use the APN shown for the ThingSIM you are installing. A saved profile from another provider is not a reliable starting point. ## Recommended plan 250 MB, UK 4-network: £1.20 a month per active SIM, ex VAT. Source: https://thingsim.com/apn-settings