Does 48 SIM have mobile data speed throttling?

[ahtams3350]

I've been using a 48 SIM card in my router and noticed a clear speed throttling issue when downloading games on Steam:

Initially, my download speed is 500Mbps (60MB/s).
However, after downloading over 20GB, the speed suddenly drops to 180Mbps (22MB/s) and stays there.
When I change the APN to internet, the speed goes back to 500Mbps (60MB/s).
But again, after downloading over 20GB, the speed drops back to 180Mbps (22MB/s).
My 5G signal is very strong, so this is clearly not a signal issue but a throttling limit.

Is 48 SIM really "unlimited" as advertised, or is this just a misconfiguration on your end? Please clarify this and provide a solution! 🙏

[dalyer]

Your attached screenshots don't seem to display properly.

And it's not really clear what your APN is initially and what you're changing it to subsequently.

To configure your APN settings correctly on a phone text "APN" to 50048 and follow the instructions here:

• https://community.48.ie/t5/The-Newsroom/APN-Settings-step-by-step-guide-for-50048/m-p/60689

For a 4G/5G router use the same key post as a guide for manually configuring them.

Download speed fluctuations are not unexpected on mobile data.

And who's to say that some may not be caused by the router itself?

You'd probably need to see if the same behaviour occurs with another router or a phone.

You'll probably have to ask 48 support about their throttling policy - if any.

I doubt that anybody here on the Community Forum is going to have any clear insight on this.

To contact 48 support see the links in my signature below.

[ahtams3350]

Thanks for your response, but your explanation does not match my real-world test results.

I have conducted extensive testing using three different 48 SIM cards across multiple devices, including:
✅ An iPhone
✅ A 4G/5G router

The results are identical in all cases:

Download starts at 500Mbps (60MB/s)
After exactly 20GB, speed drops to 180Mbps (22MB/s) and stays there
Changing the APN to internet temporarily restores 500Mbps, but after another 20GB, speed drops again
This is NOT due to:
🚫 APN settings – I tested different (48months.liffeytelecom.com,internet,3broadband.ie)APNs, and the pattern remains unchanged
🚫 Random network fluctuations – The speed drop happens at the exact 20GB mark every time
🚫 My router or device – The same behavior happens on an iPhone and a different router

Conclusion:
This is clear throttling (speed restriction) after reaching 20GB of usage.

Your response suggests you are unsure whether 48 has a throttling policy, but my results indicate that a hard limit exists.

🔹 Can you confirm whether 48 does or does not throttle speeds after 20GB of usage?
🔹 If 48 claims to offer "unlimited data," why is this restriction in place?

I expect a clear and official statement from 48 about this policy. Otherwise, advertising "unlimited data" while imposing hidden limits is misleading.

Looking forward to an official response.

[dalyer]

> Can you confirm whether 48 does or does not throttle speeds after 20GB of usage?

No, I can't. You'll need to contact 48 support and ask them.

If you need to make a complaint in order to get an official response then see the last link in my signature below.

[VilimM2002]

I have started experiencing similar set of issues. Up until 4th week of February 2025, I was getting close to 900mbps down and 60up inside my apartment in Dublin City centre (50 m away from the mast).

Now, I am lucky to get 200 down and 6-10mbps up. When I get direct line of sight to the mast, then upload speed is bigger, but download will never go above 300ish.

I am getting same behaviour with three SIM card, so I would guess Three has changed backhaul, or just borderline imposed speed caps and throttling.

Regardless, 48.ie support is instructing me to reset my APN(seriously 😒) and ignores anything else that is mentioned in the email and refuses to answer any questions regarding throttling/capping.

[dalyer]

> Regardless, 48.ie support is instructing me to reset my APN(seriously 😒) and ignores anything else that is mentioned in the email and refuses to answer any questions regarding throttling/capping.

That's very frustrating/annoying alright. ☹️

Mobile providers should be required by ComReg to clarify if/when/how they impose throttling limits on mobile data. 

I'm not sure that they are though?

[VilimM2002]

They are not required by ComReg to do much more than obey rules that are trickling down from the EU, which is so typical for Irish regulatory body. ComReg is one of the “softest” communications regulatory bodies in Europe. One can only hope things might change.

Just as I was typing this response, I got a reply from customer support after few days…

“Sorry for the inconvenience caused. As I checked the network coverage for 5g is currently down in your area and our team is working to resolve the issues but as for the 4g it’s working perfectly. And below are the network speed details which 48 provides. “

Estimated max. (download) Estimated max. (upload)
3G 2.5Mbps 0.49Mbps
4G 10Mbps 2.8Mbps
5G 25Mbps 5Mbps
—————————————————————

Now this is really funny and untrue - 5G is not down in my area, as I am connected to n78 band, which is a 5G band. The service could be downgraded or capped. I took some time out of my day to locate a few towers on the route to my work - low and behold - not at a single cell tower could I get more than 300ish down and 120up, even when looking directly at the 5G mast.

Either three/48.ie are capping individual connections, or something is really wrong with their backhaul connections.


Now don’t get me wrong, speeds we get at direct line of sight are still great(more of 4G though 😅), but changes should really be communicated to customers.
Lack of transparency just creates customer frustration and extra tickets in the backlog for customer support. I would argue being more transparent would cost 48.ie less.

[JohnW7671]

Yea i'm expierencing throttling now when using 48 sim card in my 5G modem. I'm getting max 80MB download while my phone is getting 400MB also with seperate 48 sim card.

Im at 560GB usuage for the month. I havn't seen this before. It looks like there cutting tethering speed down to 20% or maybe if you hit  a certain usage. 

I've rebooted the 5G modem and put my mobile phone 48 sim card into and getting full speeds of over 400MB, put the normal 5G router sim card back in and getting 80MB.

Definite throttling going on, especially if they tell your tethering. 

Oh well my 5G router is unlocked so will try another provider when my payment for this month is finished. I've turned off autobilling.