Check If Your SIM Is 4G and Turn On VoLTE in Pakistan: Jazz, Zong and Ufone
Poor calls or slow data? Check if your SIM and phone are 4G, switch to LTE mode, replace an old SIM and turn on free VoLTE on Jazz, Zong and Ufone in Pakistan.
To check if your SIM is 4G in Pakistan, set your phone's preferred network to 4G or LTE and see whether the 4G or LTE sign appears. On Ufone, dial *4# and the network tells you if your SIM, phone and area are ready. If the SIM is old, replace it at a franchise with your CNIC. Then turn on VoLTE, which costs nothing extra on Jazz, Zong and Ufone.
A call that breaks up every few seconds is often blamed on the tower. Quite often the real cause is in your pocket: a SIM from ten years ago, or a phone stuck on 3G. The Pakistan Telecommunication Authority (PTA) was reported on 8 October 2026 to have told users facing poor calls and unstable internet to check exactly these things first. We read what Jazz, Zong and Ufone say on their own pages. Here is the check, in the order that saves you a trip to the shop.
Three things must be 4G for 4G to work
You need a 4G-enabled SIM, a 4G-compatible phone, and 4G coverage where you are. Ufone lists exactly these three conditions on its LTE/4G page. If any one is missing, your phone drops to 3G or 2G, and calls and data get worse.
| What to check | How to check it | If it fails |
|---|---|---|
| Phone supports 4G | Look for 4G or LTE in the phone's network settings | You need a 4G phone |
| SIM is 4G | Set 4G or LTE mode and look for the 4G sign; on Ufone dial *4# | Replace the SIM at a franchise |
| 4G coverage | Check the network's coverage map for your area | Use Wi-Fi calling indoors |
| VoLTE for calls | Look for a VoLTE or 4G calling switch in settings | Check the network's VoLTE phone list |
If your phone has no 4G or LTE option at all, it is a 3G phone. No SIM change will fix that.
How to switch your phone to 4G or LTE
Open Settings, go to the mobile network section, pick your SIM, and set the preferred network type to 4G or LTE. Zong gives these steps on its 4G settings page. The names differ a little between phone brands.
- Open Settings on your phone.
- Tap SIM and Network, Connections or Mobile Network, depending on the brand.
- Choose the SIM you want to fix if the phone has two.
- Tap Preferred Network Type or Network Mode.
- Select 4G/LTE, or "5G/4G/3G/2G auto" on a 5G phone.
- Restart the phone and check the signal bar for 4G or LTE.
On an iPhone, go to Settings, Mobile Service or Cellular, then Mobile Data Options, then Voice and Data, and choose 4G or LTE. On a dual SIM phone, put the SIM you use most for data in the first slot.
If the 4G sign shows in one room and not another, the SIM is fine. That is a coverage problem, and the fixes for weak mobile signal at home apply. If you have a 5G phone, the same menu lets you enable 5G on your phone where it is available.
How to tell if your SIM is old and needs replacing
If your phone supports 4G, the mode is set to 4G, you are in a 4G area and the sign still never shows, your SIM is most likely an old 2G or 3G one. Ufone users can confirm it by dialling *4#. On other networks, ask the helpline or a franchise to check the SIM.
A quick test helps. Put a family member's newer SIM on the same network into your phone, in the same spot. If that one shows 4G and yours does not, your SIM is the problem.
Replacing it keeps your number, balance and packages. Ufone says to visit a retailer, customer service centre, franchise or Ushop to swap an old SIM for an LTE/4G SIM. You need your original CNIC and a thumb scan, because a new SIM on your number is issued only after biometric verification.
Jazz lists SIM replacement at Rs 550 for prepaid and postpaid in its FAQs. Ask at the counter before they start whether a 4G upgrade is charged the same as a lost SIM replacement. The full process for a replacement is in how to get a Jazz duplicate SIM.
Turn on VoLTE for clearer calls
VoLTE, short for voice over LTE, carries your calls on the 4G network instead of dropping to 2G or 3G. Jazz and Ufone both say it costs nothing extra. You need a 4G SIM and a phone on the network's VoLTE list.
Jazz explains the problem it fixes. Without VoLTE, a phone on 4G falls back to 2G or 3G every time a call starts. With VoLTE, the call stays on 4G, connects faster and sounds clearer. Jazz says HD calls can be up to six times better than a normal call, and you can use data during the call.
| Network | VoLTE charge | How it is turned on |
|---|---|---|
| Jazz | No extra charge | Automatic for 4G users with a supported phone |
| Ufone | No extra charge | Switch on in Settings, Mobile Networks, VoLTE; Ufone enables it from its side |
| Zong | Not stated on its VoLTE page | Check its list of 416 supported phones |
If your phone is not on the network's list, VoLTE will not work even with a new SIM. Each network's VoLTE page has a search by brand. Wi-Fi calling is the other way to make clear calls indoors, and the steps to turn on Wi-Fi calling work alongside VoLTE.
When the problem is not your phone or SIM
If your SIM shows 4G and VoLTE is on, but calls still drop, the fault is likely on the network side. Complain to your operator with the exact location and time. If it is not fixed, go to PTA on 0800-55055.
Power cuts, fibre cuts and busy towers all hurt service, and no phone setting can fix those. PTA's April to June 2026 survey shows how each network did in your city, summarised in the best mobile network in your city. The steps to complain about your mobile network to PTA explain what to send.
One small warning from Ufone. A 4G connection can use a tiny amount of data even when mobile data is off. If you have no bundle, switch the phone to 3G when data is off, or turn on balance save.
Common questions
How do I check if my SIM is 4G?
Set your phone's preferred network to 4G or LTE in a 4G area. If the 4G sign never appears on a 4G phone, the SIM is probably old. Ufone users can dial *4# to check.
Is a 4G SIM upgrade free?
Not always. Jazz lists Rs 550 for a SIM replacement in its FAQs. Ask the franchise for the exact charge before they issue the SIM.
Will I lose my number or balance if I change to a 4G SIM?
No. A replacement SIM keeps your number. You need your original CNIC and a thumb scan.
Does VoLTE cost extra on Jazz or Ufone?
No. Both Jazz and Ufone say VoLTE has no extra charges. It works with a 4G SIM and a supported phone.
Why does my 4G phone show 3G during calls?
Without VoLTE, phones drop to 2G or 3G for voice calls. Turning on VoLTE keeps calls on 4G if your phone supports it.
Do I need a new SIM for 5G?
That depends on the network. The answer for Jazz, Zong and Ufone is in do you need a new SIM for 5G.
How we verified this
What we checked, where we read it, and what we could not confirm.
Last checked on 9 October 2026. Sources: Ufone's LTE/4G quality service page and its VoLTE page; Jazz's VoLTE page and FAQs; and Zong's 4G SIM settings and VoLTE pages. PTA's 8 October advisory was reported in the press, but we could not find it on PTA's website, so nothing here is quoted from it.
About the author
Technology Journalist & Multimedia Producer
Ahmad Ali is a technology journalist and multimedia producer at Pakistan Era, joining the team in October 2026. He covers consumer technology and digital life for Pakistani readers, combining research with hands-on product testing.
