One NZ vs Mercury Mobile
One NZ wins all 3 usage types on value. One NZ has the cheaper entry-level plan. One NZ has the highest-scoring plan for value and features. One NZ uses the One NZ network and Mercury Mobile uses Spark, so check coverage where you live and work.
Prices checked 12 October 2026
| Feature | One NZ | Mercury Mobile |
|---|---|---|
| Network | One NZ | Spark |
| Plans listed | 11 | 5 |
| Cheapest plan (per month) | $10.00 | $19.00 |
| Cheapest unlimited | $88.00 | None |
| Best SmartScore | 7.4 | 6.2 |
| Prepay plans | Yes | No |
| Pay monthly plans | Yes | Yes |
| eSIM | Yes | – |
| 5G | Yes | – |
| WiFi calling | Yes | Yes |
Which should you choose?
Light use
Under 5GB: messaging, maps, a bit of social
- One NZBetter value
- Rollover Large3GB/mo · $30/mo · 7.4/10
- Mercury Mobile
- 1.25GB Rollover Data1.25GB/mo · $19/mo · 6.2/10
One NZ's Rollover Large (3GB/mo, $30/mo) costs more than Mercury Mobile's 1.25GB Rollover Data (1.25GB/mo, $19/mo), but scores higher (7.4 vs 6.2) for what you get.
Everyday use
5GB to 40GB: streaming music, social and some video
- One NZBetter value
- Endless Starter6GB/mo + endless · $50/mo · 6.1/10
- Mercury Mobile
- 5GB Endless+ Data5GB/mo + endless · $39/mo · 2.6/10
One NZ's Endless Starter (6GB/mo + endless, $50/mo) costs more than Mercury Mobile's 5GB Endless+ Data (5GB/mo + endless, $39/mo), but scores higher (6.1 vs 2.6) for what you get.
Heavy use
40GB+ or unlimited: lots of video, hotspotting
- One NZBetter value
- Unlimited PrepayUnlimited · $88/mo · 6.4/10
- Mercury Mobile
- 50GB Endless+ Data50GB/mo + endless · $59/mo · 3.5/10
One NZ's Unlimited Prepay (Unlimited, $88/mo) costs more than Mercury Mobile's 50GB Endless+ Data (50GB/mo + endless, $59/mo), but scores higher (6.4 vs 3.5) for what you get.
Choose One NZ if…
- You want the better plan for light, everyday and heavy use
- You want the cheapest way in (from $10/mo)
- You want prepay, with no bill or credit check
- One NZ coverage is better where you live
Choose Mercury Mobile if…
- Spark coverage is better where you live
Every One NZ and Mercury Mobile plan
| Plan | Calls | ? | ? | Actions | |
|---|---|---|---|---|---|
One NZRollover Large | 3GB/moRollover | Unlimited | $30/moPaid monthly | 7.4/10 | View deal |
One NZRollover Small | 1GB/moRollover | Unlimited | $18/moPaid monthly | 7.3/10 | View deal |
One NZStarter Prepay | 250MB/mo | 100 mins | $10/moPaid monthly | 7.0/10 | View deal |
One NZUnlimited Prepay | Unlimited | Unlimited | $88/moPaid monthly | 6.4/10 | View deal |
One NZOne Plan | Unlimited | Unlimited | $88/moPaid monthly | 6.4/10 | View deal |
Mercury Mobile1.25GB Rollover Data | 1.25GB/moRollover | 250 mins | $19/moPaid monthly | 6.2/10 | View deal |
One NZEndless Starter | 6GB/mo + endless | Unlimited | $50/moPaid monthly | 6.1/10 | View deal |
One NZEndless Starter | 6GB/mo + endless | Unlimited | $50/moPaid monthly | 6.1/10 | View deal |
Mercury Mobile2.5GB Rollover Data | 2.5GB/moRollover | 350 mins | $29/moPaid monthly | 6.0/10 | View deal |
One NZRollover Medium | 2GB/moRollover | Unlimited | $23/moPaid monthly | 5.6/10 | View deal |
Mercury Mobile50GB Endless+ Data | 50GB/mo + endless | Unlimited | $59/moPaid monthly | 3.5/10 | View deal |
One NZLite Plan | 3GB/mo | Unlimited | $40/moPaid monthly | 3.3/10 | View deal |
One NZEndless Plus | 50GB/mo + endless | Unlimited | $73/moPaid monthly | 3.3/10 | View deal |
One NZEndless Plus | 50GB/mo + endless | Unlimited | $73/moPaid monthly | 3.3/10 | View deal |
Mercury Mobile5GB Endless+ Data | 5GB/mo + endless | Unlimited | $39/moPaid monthly | 2.6/10 | View deal |
Mercury Mobile150GB Endless+ Data | 150GB/mo + endless | Unlimited | $79/moPaid monthly | 2.2/10 | View deal |
Frequently asked questions
Which is better, One NZ or Mercury Mobile?
One NZ wins all 3 usage types on value. One NZ has the cheaper entry-level plan. One NZ has the highest-scoring plan for value and features. One NZ uses the One NZ network and Mercury Mobile uses Spark, so check coverage where you live and work. Light use: One NZ's Rollover Large (3GB/mo, $30/mo) costs more than Mercury Mobile's 1.25GB Rollover Data (1.25GB/mo, $19/mo), but scores higher (7.4 vs 6.2) for what you get. Everyday use: One NZ's Endless Starter (6GB/mo + endless, $50/mo) costs more than Mercury Mobile's 5GB Endless+ Data (5GB/mo + endless, $39/mo), but scores higher (6.1 vs 2.6) for what you get. Heavy use: One NZ's Unlimited Prepay (Unlimited, $88/mo) costs more than Mercury Mobile's 50GB Endless+ Data (50GB/mo + endless, $59/mo), but scores higher (6.4 vs 3.5) for what you get.
Is One NZ or Mercury Mobile cheaper?
One NZ’s cheapest plan is Starter Prepay (250MB/mo) at $10.00 a month. Mercury Mobile’s cheapest is 1.25GB Rollover Data (1.25GB/mo) at $19.00 a month.
Do One NZ and Mercury Mobile use the same network?
No. One NZ uses One NZ and Mercury Mobile uses Spark.
Can I switch from One NZ to Mercury Mobile and keep my number?
Yes. Sign up with Mercury Mobile and ask to transfer your number. They’ll handle the switch, and you don’t need to cancel with One NZ first.