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SMARTY Internet Not Working Fix Guide
Ordered by how often each is the real cause, these steps for Three start with outage and APN checks before hardware.
As an MVNO, Smarty doesn't operate its own masts — it buys wholesale access to Three's infrastructure. That means a Three network outage will affect Smarty too, and the fastest way to confirm a wider problem is to check Three's live status page rather than assuming it's a fault with your phone.
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Step 1: Check for SMARTY Network Outage
Before changing any settings, check whether SMARTY is experiencing a network outage in your area. An outage is the most common reason for sudden mobile data loss across an area.
Check SMARTY status: https://www.three.co.uk/support/network-and-coverage/service-status
If there is a confirmed outage in your area, no settings changes will help — wait for SMARTY to restore the network and check the status page for estimated recovery time. You can also check Downdetector for user-reported issues.
Step 2 — Quick Smarty Fixes to Try First
Go through these five checks in sequence — together they resolve the large majority of SMARTY data faults without needing to touch APN settings at all.
- Cycling Aeroplane Mode for 30 seconds forces the fastest clean re-registration.
- A complete restart clears cached network data that a simple toggle sometimes leaves behind.
- Double-check Mobile Data is enabled: Settings › Mobile Data (iPhone) or Settings › Connections › Mobile Data (Android).
- Look at your data balance in the SMARTY app — running out of allowance produces symptoms that look exactly like a network fault.
- Reseating the SIM (power off first) fixes intermittent drops caused by a marginal contact.
Step 3: Verify SMARTY APN Settings
An incorrect APN is a leading source of data problems, especially following a factory reset, OS update, SIM swap, or a move from another network. Check and correct it if needed.
Correct SMARTY APN: smarty
How to check APN settings on Android
- Navigate to Settings › Connections › Mobile Networks › Access Point Names (Samsung) or Settings › Network & internet › Mobile network › Access point names (Pixel).
- Open the SMARTY APN entry and confirm it reads exactly smarty — watch for extra spaces.
- Check APN Type includes at minimum default and supl.
- If the entry is missing or wrong, the SMARTY APN settings guide has the full set of values.
- Save, activate with the radio button, and restart.
How to check on iPhone
- Look at Settings › Mobile Data › Mobile Data Network, if shown.
- Confirm it displays smarty.
- If greyed out, the carrier bundle manages it — check Settings › General › About for an update.
Step 4 — More Advanced Smarty Fixes
- If there's a pending update, update your phone's OS: Settings › System › Software Update — this occasionally resolves registration faults on its own.
- For iPhone, look for a carrier settings update via Settings › General › About and install if offered.
- Reset network settings as a next step: Android — APN settings, ⋮ › Reset to Default. iPhone — Settings › General › Transfer or Reset iPhone › Reset › Reset Network Settings. This wipes saved Wi-Fi passwords too.
- Try the SIM elsewhere — working there points to the handset, not the network or SIM.
- Test a different SIM in your phone — if that one connects fine, your SMARTY SIM or account is the likely cause.
- Request a free SIM replacement from SMARTY if the problem persists after all of the above.
- Call SMARTY support on help for an account-level check — they can also confirm whether there's a known issue with your local mast.
Common Causes of SMARTY Data Not Working
| Symptom | Likely Cause | Fix |
|---|---|---|
| After factory reset / phone change | APN settings not transferred | Re-enter APN settings: smarty |
| Sudden data loss, was working before | Network outage or SIM registration issue | Check status page; toggle Aeroplane Mode |
| Signal bars showing but no internet | Incorrect APN or data plan expired | Verify APN; check data balance in the SMARTY app |
| Data works then stops randomly | Poor signal, congestion, or SIM contact issue | Reseat SIM; check coverage map |
| Works on Wi-Fi but not mobile data | Mobile data toggle off or APN wrong | Enable mobile data in Settings; verify APN |
| Very slow speeds (not outright broken) | Data throttling, network congestion | Check if data cap hit; try different time of day |
| After iOS/Android update | OS update overwrote network settings | Reset network settings and re-enter APN |
Frequently Asked Questions — SMARTY Internet Not Working
How do I fix SMARTY mobile data not working?
Start with Aeroplane Mode — on for 30 seconds, then off — which re-registers your phone on the network and fixes many cases outright. If data is still down, confirm the APN under Settings › Mobile Networks › Access Point Names reads exactly smarty. Also worth checking https://www.three.co.uk/support/network-and-coverage/service-status for a known outage. If it's still not working after that, restart the phone and re-enter the APN from scratch.
What is the SMARTY APN for mobile data?
smarty is correct. The SMARTY APN settings guide has the rest of the fields too, in case you need to set up MMS or check the values on a second device.
Is SMARTY down right now?
Begin with https://www.three.co.uk/support/network-and-coverage/service-status for SMARTY's official outage status. If it looks fine there but you're still having trouble, Downdetector sometimes picks up localised issues faster.
Why does SMARTY show signal but no internet?
Seeing signal bars only confirms network registration on the mast — it says nothing about whether data is actually flowing. Verify: Mobile Data is on in Settings, APN matches smarty exactly, you haven't exhausted your data allowance, and there's no outage in your area right now.
How do I reset SMARTY APN settings?
On Android, open APN settings and tap ⋮ › Reset to Default. iPhone users: Settings › General › Transfer or Reset iPhone › Reset › Reset Network Settings — this wipes Wi-Fi passwords as a side effect, so have those handy. Re-enter smarty afterwards.
SMARTY data stopped working after a phone update — what do I do?
This is a frequent side effect of OS updates overwriting custom network settings. Go to Settings › Mobile Networks › Access Point Names and put smarty back in. iPhone owners should also check Settings › General › About for a carrier update, then restart.