The phone suddenly feels painfully slow. Photos on LINE spin, a video sits there after you tap it, and looking up a map outside means waiting again and again. It is easy to blame the signal, until the carrier app makes it obvious: the high-speed data for this billing cycle ran out a while ago.
The awkward part is that the next reset may be only 3 or 5 days away. Switching to a more expensive monthly plan for those few days does not seem worth it. Limping along until the reset is genuinely miserable, though.
There is more than one way through it. You can check whether your current carrier has an add-on that fits, or you can use a second, short-term eSIM as a temporary data line. Keep your original Taiwan number, keep receiving calls and texts, and switch only mobile data to the new eSIM. For someone who just needs to get through the last few days, that is a flexible option.
An eSIM is not the cheapest choice every time, and buying one does not guarantee that 5G comes back instantly. This article lines up official add-on information from the three major carriers, the JEKO Taiwan plans, the install steps, and the spots that are easy to get wrong, so you can compare them and pick the one that actually fits.
Start here: If you only need 1 day, your carrier’s 1-day unlimited add-on may already be the convenient choice. If you need extra data, want to keep your original number, do not want to touch the monthly contract, and your phone supports dual-SIM eSIM, put a short-term JEKO Taiwan eSIM on the comparison list. A real comparison lines up the same number of days, a similar amount of data, and the throttle rule after the quota runs out.
1. Why does the phone become unbearable the moment the data runs out?
Not every plan called unlimited keeps the same speed from start to finish. Plans you commonly see in Taiwan fall into about 3 types: a fixed high-speed quota that throttles when it is used up; a speed-capped unlimited plan whose maximum rate is set from the beginning; and a plan that offers uncapped data under its own conditions.
The first type is the one that feels like yesterday was fast and today is suddenly crawling. You may have a set amount of 5G high-speed data in each billing cycle, and once that quota is gone the system lowers the speed according to the contract. How far it drops depends on the carrier and the plan you signed up for. Not everyone is dropped to 128Kbps.
How slow is 128Kbps? In ideal conditions, that rate can theoretically move only about 16KB of data per second. A text message might still squeeze through, but loading a map, short video, web images, or a video call becomes a struggle. High-definition video is out of the question, and even a shopping page full of pictures can feel like something you want to give up on.
The other way around: if your plan is already a speed-capped unlimited plan with a fixed maximum of 10Mbps, that does not mean the data ran out at the end of the month. The cap may have been there from day 1. Before you buy a short-term eSIM, it is worth confirming which of these situations you are actually in.
The National Communications Commission (NCC) 2025 communications market survey found that, among mobile internet users surveyed, 56.6% were on uncapped unlimited plans and 16.7% were on speed-capped unlimited plans. Metered plans of various kinds added up to about 18.5%. That means not everyone in Taiwan is on an uncapped, unlimited plan. These figures describe which plans people chose. They are not a count of how many people are definitely throttled at the end of every month.
One small thing that is easy to miss: what people call the end of the month is really your billing cycle. Some high-speed quotas reset on the 1st of each month, and some do not. The date to check is the next reset shown in the app, not a habit of waiting until the 31st.
2. Do not buy yet. Take 1 minute to check whether the data really ran out
A slow phone is not always a throttle. It can be a congested cell tower, weak indoor reception, an unstable VPN, the phone downloading an update, or Wi-Fi that has already dropped. These 4 checks keep you from spending money you do not need to spend.
- Open your carrier’s official app. Look at the remaining high-speed data, the plan name, the speed after you go over the quota, and the next reset date. The carrier’s billing system is the reference. It is more accurate than the total your phone adds up on its own.
- Turn Wi-Fi off and test mobile data. Go somewhere with a better signal on purpose and open an ordinary web page. If the speed comes back when you change location, the problem may be reception rather than data.
- Check for heavy background use. A system update, a cloud photo backup, or video that plays on its own can eat a large chunk of data in a short time.
- Estimate how many days you still need to get through. Half a day left and 7 days left can call for completely different, and differently priced, fixes.
Only after you see that the high-speed quota really is at zero should you compare ways to add data. If you are already on a fixed-speed unlimited plan, confirm that you actually need a second line before you buy one.
3. What do Taiwan carrier data add-ons cost in 2026? Start with the official prices
A lot of people assume an add-on from their own carrier has to be expensive. That is not always true. The rows below are publicly listed official add-on prices found in October 2026. Whether you can actually buy one still depends on your 4G or 5G plan, your postpaid eligibility, and the promotion in force.
| Carrier and plan type | Add-on example listed officially | Price | What to watch |
|---|---|---|---|
| Chunghwa Telecom 5G postpaid add-on | 1GB / 3GB / 5GB | NT$150 / 360 / 550 | Use it under the plan and billing cycle it applies to |
| Chunghwa Telecom 4G timed add-on | 1 day / 3 days / 5 days | NT$120 / 300 / 450 | Listed on the official site under the 4G column. The 5G data column does not list the same item |
| Taiwan Mobile 5G customers who are not on unlimited | 2GB / 5GB / 8GB | NT$200 / 400 / 550 | Check the hotspot-sharing terms and whether your account qualifies |
| Taiwan Mobile 5G customers who are not on unlimited | 1-day / 3-day unlimited | NT$120 / 300 | The official site shows the offer through 2026/12/31. You still need to confirm eligibility |
| Taiwan Mobile 4G add-on | 500MB / 2GB / 3GB | NT$100 / 250 / 350 | Do not mix 4G and 5G and treat them as the same kind of plan when you compare prices |
Both Chunghwa Telecom and Taiwan Mobile offer add-ons you can order online, so this does not have to mean a store visit or a contract change. If you simply need a lot of data today, a day-based plan from your own carrier can be less hassle than installing another eSIM.
FarEasTone’s public add-on terms differ across its plans and projects. Check the FarEasTone app, or the detail page for your own plan. Do not copy the rate on someone else’s contract onto your number.
Official prices and sign-up pages:
- Chunghwa Telecom: 5G/4G mobile data add-ons
- Taiwan Mobile: domestic 4G/5G data add-ons
- FarEasTone: rate notices and plan descriptions
4. Can a short-term eSIM cover the gap, and how is it different from a carrier add-on?
It can, once this point is clear: A JEKO Taiwan eSIM is an extra data line. It does not put the high-speed quota back on your original monthly plan.
You do not have to cancel your Chunghwa Telecom, Taiwan Mobile, or FarEasTone number, and you do not have to pull out the physical SIM. If the phone can run two suitable SIM lines at the same time, the original number can take calls and bank verification codes while the JEKO eSIM handles internet access.
That is a particularly good fit when the data resets in 3 to 5 days, because you may not want to change the monthly plan and you may not want a long-duration product. If the carrier add-on is cheaper and easier to use, choosing the carrier first is completely reasonable.
| What you are comparing | Add-on on your monthly plan | Carrier prepaid | JEKO Taiwan short-term eSIM |
|---|---|---|---|
| Your original number | Data is added on the original line | A newly applied prepaid card is usually a different number | You can keep the original number and use the eSIM for data |
| How you sign up | Official app, website, customer service, and similar channels | A new number involves identity checks. An existing prepaid card can be topped up online | The product page says no ID upload. Buy and install online |
| How soon you get it | After a successful add-on, it starts on the carrier’s activation timing | It depends on whether you already have a prepaid number | After the QR code is delivered electronically, you still have to download it and register on the network |
| How the price is counted | By GB, by hours, or by days | By the prepaid top-up plan | By days, daily allowance, total data, or a speed combination |
| Main limit | You must qualify under your current monthly plan | A first-time application may mean going through the signup process | The phone must support eSIM. Watch the validity period and the exit IP |
| Who it suits | People who want high speed back on the original number | People who already have a prepaid card they can top up | People who want one extra short-term data line and do not want to touch the original number |
If you already have a prepaid number you can top up, do not leave it out of the comparison. Topping up an existing prepaid card can be convenient. Do not treat a first visit to a store to apply for a prepaid card as a step every prepaid user has to take.
5. What kinds of JEKO Taiwan eSIM are there, and how do you avoid buying the wrong one?
The JEKO Taiwan section currently shows 3 main product types: daily, total data, and unlimited. The starting prices on the category list found in October 2026 are from NT$59 for daily, from NT$109 for total data, and from NT$189 for unlimited.
That word “from” matters. It is the lowest starting price on the product list. It does not mean every duration or every data option sells at that price. If you need 5 days in a row at 2GB a day, you have to open that spec to see the actual checkout price. You cannot take NT$59 and say how much cheaper it is than a carrier’s 3-day plan at NT$300.
1. Daily: the last few days are mostly chat, maps, and social feeds
Each day comes with a set high-speed quota. On some options, once that quota is used the speed drops to about 128Kbps, and a fresh high-speed allowance returns the next day. There are also extra speed-capped options you can keep using. This fits when you need some high-speed data every day and your usage stays fairly steady.
Picture 4 days left at the end of the cycle. Each day you mainly send LINE messages, call a ride, check the map, and scroll a social feed. You may not need a large total-data pack. A daily plan can be the right size.
Be careful, though. If one day you suddenly go live or keep watching video and burn through that day’s high-speed quota, the remaining 128Kbps is not a speed for binge-watching. Before you buy, read how many GB of high-speed you get each day, and what speed you drop to after that.
View the JEKO Taiwan daily eSIM
2. Total data: heavy use today, very little tomorrow
A total-data plan does not hand you the same high-speed quota again every day. You share one pool of data across the valid days. Some days you may navigate for a long time or share a hotspot in a meeting, and another day you may be on Wi-Fi almost the whole time. A total-data plan is more flexible in that pattern.
Depending on the operator and the spec, a total-data plan may simply disconnect once the high-speed data is used up, or it may continue at a lower speed. That is the detail most worth checking before you buy. Do not stop at “it has 10GB”. Also see what happens after the high-speed quota is gone.
View the JEKO Taiwan total-data eSIM
3. Unlimited: a few days you want to use with less worry, if you read the speed terms
Unlimited does not mean uncapped, with no conditions, the whole way through. The description on some JEKO Taiwan unlimited products is a daily high-speed quota first, then continued use at about 5Mbps or 10Mbps. That speed usually helps with everyday messages, ordinary web pages, and some video, but heavy downloads, a hotspot shared with several people, or a high-definition livestream still need a separate judgment.
One reminder in particular: you can be online in Taiwan while the route and the exit IP of different eSIM supply plans are in Hong Kong or Singapore. Some banks, video platforms, games, region-locked services, or AI tools may limit features because of where the IP is. If you depend heavily on a Taiwan IP, confirm that before you buy.
View the JEKO Taiwan unlimited eSIM
6. Which one actually costs less? Three real end-of-cycle situations
Scenario A: The reset is 1 day away, and the high-speed data is already gone.
Open the carrier app first. On the public information available now, Chunghwa Telecom’s 4G timed add-on and many eligible Taiwan Mobile 5G add-ons both have a 1-day option at NT$120. If you are on Chunghwa Telecom 5G, do not treat that 4G timed price as the price you yourself can order. If you only need this 1 day and you want data back on the original number, this route is worth looking at first. If JEKO has a lower-priced plan that matches the days and the usage, compare that too, and count the install steps plus the time you still have today.
Scenario B: You still need 3 to 5 days, mostly for LINE, maps, and social feeds.
Put the JEKO daily plan next to your carrier’s 3-day add-on. What matters here is not only the starting price. It is the total price for those 3 to 5 days, and the high-speed quota per day. If the carrier add-on is 3 days for NT$300, a matching JEKO 3-day plan is the better value only when the total price, the high-speed amount you can use each day, and the throttle terms all fit what you need.
Scenario C: You burn through data, and you also need to share it with a laptop.
Estimate roughly how many GB you need, then look at total data or unlimited. If you will be on video calls for a long time or updating large files, do not decide from the word unlimited alone. Hotspot support, the speed after the high-speed quota, reception where you are, and how much the laptop uses are the real points. For a heavy user, the carrier add-on can also be the better fit, because it uses the local network conditions you already know.
A simple order works: Count the days you have left, then how much high-speed you need, and only then compare the total price. You do not need to buy an eSIM just so you can say you use one, and you do not need to assume a big carrier brand is always more expensive.
7. Data ran out. How do you add a connection with a JEKO eSIM?
The point of this method is that data goes through the new line, while calls and texts stay on the old one. Confirm two things first. The phone itself supports eSIM, and it can keep your original number and the new eSIM enabled at the same time. Then, connect to stable Wi-Fi before you start. Downloading an eSIM needs a network. You cannot install it with no connection at all.
iPhone: keep the original number for calls, and move mobile data to JEKO
- Buy a JEKO Taiwan eSIM that matches the days, the data, and your device, and get the install details from the order.
- On Wi-Fi, open Settings → Cellular → Add eSIM, then scan the QR code from the order email or install it in another way the order supports.
- Name the new line something like “month-end data” so it is harder to pick the wrong one.
- Go to Settings → Cellular → Cellular Data, and select the JEKO eSIM you just installed.
- If you do not want the phone to switch back to the original number and spend that data on its own, turn off Allow Cellular Data Switching. After you turn it off, some calls may not be able to use data on the other line at the same time.
- Leave Default Voice Line on your original Taiwan number. If you need texts, confirm that the original number is still on and can receive them.
- Set data roaming according to that eSIM product and the order notes. Some Taiwan eSIMs are roaming-type lines, so this switch may need to be on. Turn it on for the JEKO eSIM line, not casually on your original number.
- Turn Wi-Fi off and try a web page. If it does not work, check the new line, the data selection, roaming, and the APN first. Do not rush to delete the eSIM.
Samsung / Android: the same job is changing the default SIM for mobile data
On a Samsung Galaxy, the usual path is Settings → Connections → SIM manager. Add the eSIM while you are on Wi-Fi. After it is installed, assign mobile data to the new eSIM, and leave calls and texts on the original number. The labels can differ a little across Galaxy versions.
On a Google Pixel, the usual path is Settings → Network & internet → SIMs. Assign Calls, Messages, and Mobile data to the SIM you want for each. A new line that simply says it is enabled does not mean the data has switched over by itself.
If the phone finishes installing and still will not connect, check the order email for an APN or a roaming setting, then contact JEKO support. Some travel eSIM QR codes can be downloaded successfully only once. Do not delete the eSIM and start over while you have no connection.
A practical note: you do not have to delete the line the moment you are done
After your carrier’s high-speed data resets, switch Mobile Data back to the original number first. When to delete the eSIM depends on the product rules, whether you still need it, and whether you can install it again later. Deleting it usually does not pause a validity period that has already started, and scanning the original QR code again does not guarantee that you can download it a second time.
8. Five small things to read before you buy a short-term eSIM
The phone has to support eSIM, or the purchase will not help. Not every Android phone, and not every regional version of a phone, supports eSIM. Even if the model name looks the same, confirm that the phone’s own settings include a way to add an eSIM. If the phone is carrier-locked, also confirm that it can use another provider’s eSIM.
Scanning the QR code does not guarantee you will be online within 3 minutes. Electronic delivery skips shipping and a store visit, but the download, the check, finding a cell tower, and activation all take time. A delayed email, a payment risk check, or device compatibility can also slow things down. If this is a last-minute fix, have Wi-Fi ready first.
“No ID upload” is a condition of that product, not a rule for every eSIM. Some JEKO Taiwan product pages say you do not upload ID documents. Different issuers, products, uses, and regulatory requirements can differ. Do not stretch that into a promise that anyone, on any plan, is guaranteed to need no identity check.
A Hong Kong or Singapore IP is not a Taiwan IP. Most everyday websites may work as usual, but region-locked services and some login checks can behave differently. If your work requires a Taiwan IP, ask support about the line’s exit before you buy.
Do not compare a regular price with a promo price, and do not compare the wrong unit. 500MB a day and one 5GB pack are not the same product. 128Kbps after the high-speed quota and 5Mbps after the high-speed quota are not the same experience. A real comparison looks at a similar validity period, the total high-speed data you can use, and the throttle rule.
9. Not planning to spend more? Try these ways to use less data first
If you have only 1 day left and you already have Wi-Fi at home or at the office, you may not need to buy anything extra. Adjust the things that use the most data, and you can often stretch a little further.
- Turn on Low Data Mode in the phone settings, or Data Saver on Android, to cut some background data.
- Set Google Photos, iCloud Photos, and cloud-drive backups to run only on Wi-Fi.
- Lower streaming quality, and use Wi-Fi before you go out to download offline music or videos the app allows you to save.
- Turn off autoplay for social video you do not need, so short clips do not keep running in the background.
- Use Wi-Fi to download a map area you can open offline. Live traffic, and some route features, still need a network.
- Check the carrier app for a promotion or a data gift that applies to you right now. You may not need to spend anything else.
You can treat a short-term eSIM as a backup for when the connection is not enough. It does not have to become a fixed expense at the end of every month.
10. FAQ
If my mobile data runs out, do I have to wait until next month for it to come back?
Not necessarily. Check the reset date on your current monthly plan first. If you qualify, you can also buy an add-on from the carrier, or use an extra data eSIM for temporary internet access. Different plans may cap the speed, throttle it, or stop providing data.
If I am throttled to 128Kbps at the end of the cycle, can I still use LINE?
A small amount of plain text may go through, but photos, voice messages, video, and web pages can be very slow, and the state of the connection still affects the result. 128Kbps is not a normal speed for video and browsing.
Is a JEKO Taiwan eSIM cheaper than a Chunghwa Telecom or Taiwan Mobile add-on?
It depends on the days and the data you pick. The JEKO section has lower starting prices, but you cannot compare “from NT$59” directly with a 1GB or 3GB carrier add-on. Choose the spec on the JEKO product page first, then match that same need against the current price in your carrier’s app.
If I buy an eSIM, does my original mobile number disappear?
Adding a data eSIM does not automatically cancel your original number. If the phone can run dual SIM at the same time and the original line stays on, you can usually keep calls and texts and give internet access to the new eSIM.
Can I still receive bank OTP texts?
In most cases, yes, as long as the original number stays enabled, has a normal signal, and you have not turned it off or switched it away yourself. A JEKO data-only eSIM does not receive the bank texts that belong to your original number, so you still rely on that number.
Is an eSIM always 5G?
Not necessarily. The networks the product supports, the local cell towers, the phone’s bands, and the signal all affect the connection you actually get. A 5G icon on the phone does not guarantee a fixed high speed every second.
If I have no Wi-Fi, can I install the eSIM when my original data has already run out?
If the original number can still connect well enough to finish the download, it may be possible. If you have no network at all, you usually need trusted Wi-Fi, or another usable network, before you can download the eSIM. Do not treat an eSIM as a product you can turn on completely offline.
Does a JEKO Taiwan eSIM require me to upload an ID?
Some JEKO Taiwan plan pages currently say no real-name check and no ID upload. Follow the actual product conditions and the rules that apply at the moment you buy. Do not assume every telecom product works the same way.
Can the eSIM share a hotspot with a laptop?
Some JEKO Taiwan plan pages say hotspot is supported. You still need to check the spec you selected, the high-speed data you have left, the speed after throttling, and the phone settings. Syncing files on a laptop often uses more data than the phone itself.
When the original data comes back, how do I switch back?
In the phone’s mobile data or SIM settings, switch the default internet line back to the original number. Confirm that data on the original number is working normally again, then decide whether to turn the other eSIM off.
Can a short-term eSIM replace my monthly plan?
It is usually not a good idea to treat a data-only eSIM as a full replacement for a voice monthly plan. It does not have your original mobile number, ordinary phone calls, or text service, and it has time and data limits. This article is about bridging a short gap, not about changing your number completely.
For a rush, which fits better: a carrier data add-on or a newly bought eSIM?
A carrier add-on usually skips the step of installing a new line, so it suits people who want to keep using the original line. A short-term eSIM suits people who need a separate data line, whose phone is compatible, and who have found a better match for the days and the usage. When you are in a hurry, pick the method you are confident you can finish right now.
Closing: three days without usable data is not a reason to rush into a new monthly plan
The irritation of a throttled phone near the end of the cycle is familiar. You only wanted to reply to one LINE message and check a map, and because the data ran out the whole phone feels about 10 times slower.
The next step is not to buy the most expensive unlimited plan immediately, and it is not to check out with your eyes closed because an eSIM is labeled cheap. Check your current plan and the reset date, compare the carrier add-on with a short-term eSIM, and find the option that gets you through these few days. That is the sensible way to choose.
If you want to keep receiving calls and OTP on your original number, and hand only internet access to the other line, take a look at the JEKO Taiwan short-term eSIM plans. After you pick the days and the data, confirm the product spec, the final price, phone support, and the activation conditions, then decide whether to buy. Make the data fix simpler, and spend just enough.
The rates and product-page details in this article were checked on October 26, 2026. Promotions, data specs, routes, and eligibility can change. Before you buy, the live spec and the checkout amount on each carrier’s page, or on the JEKO product page, are the source of truth.
