Running out of data before your validity ends is annoying, and the instinct is to move up to a bigger plan permanently. For most people that is the expensive answer.
Add-ons usually beat upgrading
If you only run short occasionally, a small add-on on those days costs less than permanently paying for a larger plan every single month. You are buying data for the two or three days you need it, not for thirty.
Upgrading is the right call only when you run out most months. If it happens twice a year, add-ons win comfortably.
Two ways to size it wrong
Too small. You buy the cheapest pack, it covers a day and a half, and you buy a second one. Two small packs almost always cost more than the single correctly-sized pack you skipped.
Too large. You round up for safety and the unused portion expires with your plan. Add-on data usually does not roll over — it normally dies with the validity of the plan it sits on. Paying for headroom you will not reach before expiry is just paying.
How to actually size it
Do not guess from your monthly total. Work out the gap:
- Note the day your data usually runs out.
- Count the days left in your validity after that.
- Multiply by your normal daily use.
That number is the gap. Buy the smallest pack that covers it. If your plan runs dry with five days left and you use about a gigabyte a day, you need roughly five gigabytes — not two, and not twenty.
One thing worth checking first
Some plans slow you down after your daily allowance rather than cutting you off. If the reduced speed is enough for messaging and maps, you may not need an add-on at all on a light day. Check what your plan does at the limit before you spend anything.
For the add-on packs currently on offer, see all plans and use the Data pack filter.