You buy a bundle on Monday. By Thursday lunchtime the same message appears again: you are almost out of data. Nothing unusual happened. No streaming marathon, no big downloads. You used WhatsApp, checked your banking app, and watched a few clips over lunch.
If that sounds familiar, the problem is not your discipline. Data and airtime are one of the easiest places for money to leak out of a South African budget. Each top-up feels small, so none of them ever make it onto a budget sheet, yet together they can rival a utility bill.
Here is the short version of what this guide covers:
- Work out what you really spend each month, including every small top-up.
- Understand why bigger bundles cost far less per gigabyte.
- Check your out-of-bundle and alert settings instead of assuming they are right.
- Know what ICASA's new data rules will and will not change.
- Block the services quietly billing your airtime.
- Compare networks, including the cheaper virtual networks, before you renew.
Why does your data disappear so fast?
Your data disappears fast because most apps keep working in the background even when you are not looking at them. App updates, photo backups, email syncing, autoplay video and in-app ads all use mobile data, and together they can account for a large share of a small bundle.
WhatsApp is not usually the villain people assume it is. Text messages use almost nothing. Voice notes, status videos, group photos and video calls are what pull data, especially when media downloads automatically. Open Instagram or TikTok for ten minutes and autoplay does the rest.
Do one quick test this week. Open your phone settings, find mobile data usage, and look at the last 30 days sorted by app. You will almost always find one or two apps using far more than you expected. Then switch their media auto-download and background refresh to Wi-Fi only.
How much are you really spending on data and airtime?
Most people spend more than they think, because they remember the big bundle and forget the small top-ups. Add up everything that left your account or your airtime balance in the last three months, including the R10 and R20 vouchers, and divide by three. That is your real monthly number.
Here is an illustrative month for two people in one household. Each buys about R250 of bundles and top-ups, which is R500. Add R40 for a content subscription billed to the phone. Add 80 minutes of out-of-bundle calls at R1.46 a minute, which is the average out-of-bundle voice rate in ICASA's 2025 tariff analysis, so about R117. That comes to R657 for the month, or R7,884 over a year. That is a holiday, a chunk of a car deposit or several months of a savings goal, spent on connectivity nobody was tracking.
Why do bigger bundles cost so much less per gigabyte?
Bigger bundles cost far less per gigabyte, so buying small bundles repeatedly is the most expensive way to use data. ICASA's tariff analysis of the second half of 2025 lists Telkom's prepaid ladder, which shows the pattern clearly. These are list prices at the time of the report and they change, so check your network before buying.
- 1.2GB for R79, which is about R66 a gigabyte
- 2.5GB for R149, about R60 a gigabyte
- 5.5GB for R299, about R54 a gigabyte
- 12GB for R499, about R42 a gigabyte
Now apply it. Say you really use about 10GB a month. Covering that with 1.2GB bundles takes nine of them, which is R711. One 12GB bundle is R499. The difference is R212 a month, or R2,544 a year, for the same data and a little left over. The same logic holds on other networks: ICASA's first-half 2025 report found MTN charging R89 for 1.2GB (about 7c a megabyte) and Vodacom R95 for 1.5GB, while MTN's 40GB and 60GB bundles were R720 and R800.
The catch is that a bigger bundle only saves money if you use it. That is why the usage check above comes first.
Is out-of-bundle data still a trap?
It is less of a trap than it used to be, but you should still check your settings. Under ICASA's rules, which have applied since 2019, your network may not charge out-of-bundle rates unless you have agreed to them, and you can choose to opt in or out. Networks must also send usage alerts when you reach 50%, 80% and 100% of a bundle, although you are allowed to switch those alerts off.
So do two things. Open your network's app or customer care line and confirm that out-of-bundle billing is off, and confirm that your usage alerts are on. Menus and codes differ between networks and change over time, so use the app rather than a code you found in an old forum post.
Voice is a different story. ICASA's report noted that MTN and Vodacom raised out-of-bundle voice rates during the first half of 2025, and the average out-of-bundle rate across the flat-rate tariffs it tracks was about R1.46 a minute. If you make long calls on airtime, a voice bundle or a WhatsApp call on Wi-Fi is almost always cheaper.
What is changing with ICASA's new data rules?
ICASA gazetted amended rules in January 2026 that are due to take effect in January 2027, but they are being challenged in court, so do not budget around them yet. As reported by Cape Argus, ITWeb and TechCentral, the amendments would make operators:
- Roll over unused bundles at least once, automatically and at no cost, except for bundles of seven days or less and uncapped, free or promotional bundles
- Use the bundle that expires first
- Charge out-of-bundle rates only if you explicitly opt in
- Let you transfer bundles to anyone on the same network without buying a bundle
MTN served court papers on 22 July 2026 asking for the rules to be reviewed and set aside, and Vodacom has filed its own application against parts of them. At the time of writing I found no ruling, and no report that the rules have been suspended. Until something changes, check your network's current terms: when rollover was introduced in 2019, MTN tied it to buying another bundle before the old one expired, and Vodacom to buying the same bundle again. If the rules do take effect, the days of watching a half-used bundle expire should get a lot rarer.
Where else does airtime quietly leak?
Airtime leaks through anything that bills your phone directly. WASPA, the industry body for wireless application service providers, tells people who are losing airtime to check for WASP subscriptions, premium SMS, airtime transfers and USSD competitions. Many renew every week or month until you cancel them.
These are the charges that never feel like spending. You enter one competition, you tap yes to a trial, and R5 or R10 vanishes every few days. Over a year it is the same slow drain as subscriptions quietly renewing each month, and a classic case of the small choices that drain your budget.
WASPA's consumer guidance lists these routes at the time of writing. Codes do change, so confirm with your network if one does not work.
- Vodacom: SMS STOP ALL to 31050, or dial *135# and choose Content Services, then Stop All, then Block. The Vodacom app also has a "Block content services" option.
- MTN: dial *141*5# and choose Content Services to view and cancel subscriptions. To block premium-rated charges, dial *155#.
- Cell C: dial *133*1# to block existing and future content billing.
- Telkom: in the Telkom app, go to My Products, then Manage, then Protect Your Mobile Number, and switch it on. You can also dial 180.
If charges continue after you have blocked them, you can report unwanted billing to WASPA. Also report a lost or stolen phone to your network straight away, because stolen phones are often used to transfer airtime.
How do you cut data and airtime costs without going offline?
You cut costs by matching your plan to your real habits, not by using your phone less. Work through these in order and the savings stack up:
- Check your real usage. Use your network's app to see how much data you use in a normal month, not a good month.
- Match the bundle to the number. If you use 8GB, stop buying 1GB bundles and topping up. The bigger bundle drops your price per gigabyte.
- Move the heavy stuff. Do updates, backups and downloads on Wi-Fi at home, at work or at a friend's place, and use night or off-peak data where your network offers it.
- Kill the phantom services using the codes above.
- Compare networks, including virtual ones. In ICASA's tariff analysis of the second half of 2025, Asuer Connect and Sakeng Mobile sold 30-day 1GB bundles for R35 and R40, against R85 for Cell C's standard 1GB. The first-half report found Shoprite K'nect at R39 for 1GB with 60-day validity, Old Mutual Connect at R45 with no expiry, and Capitec Connect at R60. ICASA's conclusion was that virtual network operators generally offer better value and longer validity.
- Set a fixed monthly amount for connectivity and treat it like any other bill. Once you have automated your budget, this is one more line that runs itself.
A word of caution on step five. These are 2025 prices from ICASA's filings, so confirm today's price before you move. A virtual network runs on a host network's coverage, so check it works well where you live and work. Switching also usually means a new SIM, and WhatsApp is tied to your number, so think about how you will tell people. Even so, if you are buying the same few gigabytes every month, a few minutes of comparison can be worth more than any other change on this list. It is the same idea as the swaps in how to save on a low salary.
How can Budget Hub help you see this spending?
Budget Hub gives airtime and data their own line, so the spending stops being invisible. In the monthly expenses form, "Airtime & Data" is a separate category from "Internet", so your phone and your home line do not get mixed together.
Be clear about what that line is: you enter a monthly total, not every purchase. The easy way to get an honest number is to add up the last three months from your banking app, divide by three, and update the figure whenever your habits change. It is a living figure, not a month-by-month ledger.
If your bank can export a CSV, you can also import a statement. Budget Hub groups the transactions by category and sorts payments whose description names a network or provider such as MTN, Vodacom, Telkom, Cell C or Afrihost into "Internet & Phone". Check the category on each one, because a description that does not name the provider will not be matched, and you can correct it by hand. Cash vouchers will not appear on a statement at all, and a top-up bought at a till may show under the shop's name and land in groceries, so move those to the right category yourself. The free plan allows one upload a month and reads the first 50 transactions, which is enough to see the pattern.
What is the one number to find today?
Open your banking app and add up the last three months of airtime, data, vouchers and phone-billed subscriptions. Divide by three. That is your real monthly connectivity cost, and for most people it is higher than the number they would have guessed.
Then do the two quick fixes that cost nothing: confirm your out-of-bundle billing is off and your alerts are on, and block the content services you never chose. Finding even R200 a month is R2,400 a year, and that money can finally go where you want it to. When you are ready to see the whole picture, Budget Hub is free to start.