Cheapest Unlimited Mobile Data Plans NZ (2026) – Compare Prices

Everyone who’s ever hit the data cap halfway through the month knows the feeling: buffering videos, throttled speeds, and the nagging sense that “unlimited” isn’t quite what it claims. For heavy users in New Zealand, finding a genuinely cheap unlimited mobile plan — one that doesn’t hide throttling in the fine print — has become a kind of treasure hunt. The cheapest option, Mighty Mobile’s Fast plan at $29.10 per month (MoneyHub (NZ consumer finance comparison)), offers unlimited data at a capped 50Mbps, revealing the first rule of NZ unlimited plans: the price is low, but so is the speed limit.

Cheapest unlimited plan in NZ: Mighty Mobile at $29.10/month (member price, up to 50Mbps) ·
Spark Endless 75GB plan price: $65/month ·
Major providers with unlimited/endless plans: Spark, One NZ, Mighty Mobile, 2degrees ·
Common data cap before throttling: 3GB to 75GB depending on plan

Key facts at a glance

Here are the core numbers from the major providers, compiled from official sources and comparison platforms.

Which carrier has the cheapest unlimited data plan in New Zealand?

One NZ Unlimited Data Plans

One NZ offers Pay Monthly plans with Endless and Unlimited tiers. The ‘Unlimited’ plan costs about $60/month and includes 10GB of hotspot data (One NZ). However, One NZ’s Endless plans start from $50/month with a data cap after which speeds are reduced. For heavy users, the Unlimited plan is the most relevant, but it’s not the cheapest in the market.

Spark Endless Data Plans

Spark’s Endless data plans start at $25/month for 3GB but go up to $65/month for the 75GB option. After reaching the chosen data tier, speeds are throttled to 1Mbps (Spark NZ). Spark also has a $1/day for 10MB data option for occasional use (MoneyHub). For unlimited data, the 75GB plan is the highest tier before throttling.

Mighty Mobile Unlimited Data

Mighty Mobile, an MVNO that runs on the Spark network, offers the cheapest true unlimited plan in NZ. Their ‘Fast’ plan costs $29.10/month (member price) and provides unlimited data at up to 50Mbps. An even cheaper 10Mbps plan is available at the same price, recommended by MoneyHub for its value. The catch is the speed cap: you won’t get full 4G/5G speeds, but for browsing, social media, and standard-definition video, it’s sufficient (MoneyHub).

Comparison of cheapest options

Three carriers, one pattern: all NZ “unlimited” plans have a soft cap — a threshold after which speeds drop, usually to 1Mbps. Mighty Mobile stands out by enforcing a speed cap instead of a data cap, offering consistent lower speeds for a much lower monthly price. For a heavy user needing more than 75GB, Spark’s throttled 1Mbps after cap may feel slower than Mighty Mobile’s consistent 10–50Mbps.

The implication: the cheapest plan sacrifices top-speed bursts for a steady, low monthly bill.

What is the difference between unlimited data and endless data?

Unlimited data explained

In New Zealand, “unlimited data” usually means a high data allowance followed by throttling. For example, Spark’s Endless 75GB plan gives you 75GB at full speed, then slows to 1Mbps for the rest of the month (Spark NZ). Mighty Mobile’s “unlimited” is different: you get capped speeds (10 or 50Mbps) but no data limit. Both are marketed as unlimited, but the experience differs significantly.

Endless data explained

“Endless” is a brand term used by Spark and One NZ for plans that have a data tier (e.g., 3GB, 6GB, 75GB) and then throttle to 1Mbps. Once you hit the cap, you don’t pay extra — you just get slower speeds. This is Spark’s definition of unlimited. One NZ also uses “Endless” for plans starting from $50/month, with similar throttling after the tier limit (One NZ).

Key differences: throttling, fair use, speed caps

The main difference is how the limit works. Traditional “unlimited” (Mighty Mobile) uses a speed cap — you never get full speeds, but you never get cut off. “Endless” plans (Spark, One NZ) give you full speeds up to a data tier, then throttle heavily to 1Mbps. For a heavy user who uses 100GB, Mighty Mobile’s consistent 10–50Mbps might be more usable than Spark’s 1Mbps after 75GB. However, if you only use 60GB, Spark’s full speed for those 60GB is faster than Mighty Mobile’s capped speed.

The pattern: the choice comes down to whether you prefer a consistent low speed or a burst of high speed followed by a crawl.

How to get unlimited data on One NZ?

One NZ Prepay Plus plans

One NZ offers unlimited data on its Pay Monthly plans, not on standard prepay. The ‘Unlimited’ Pay Monthly plan costs around $60/month with 10GB hotspot data. You can also choose the ‘Endless’ plan for $50/month with 3GB data before throttling (One NZ).

Steps to activate unlimited data

1. Check coverage at your address using One NZ’s coverage map.
2. Choose between Pay Monthly (Unlimited or Endless) or Prepay Plus (by adding data packs).
3. Purchase a SIM card: costs from $0 to $5 depending on plan, or use eSIM if your phone supports it.
4. Sign up online or in a store. Provide ID, choose a plan, and activate.
5. Set up auto-pay to avoid service disruption.

Cost and requirements

The SIM card cost is minimal ($0–5). Monthly bills start at $50 for Endless 3GB and go up to $60 for Unlimited. A postpaid account requires a credit check (One NZ). For travelers or short-term use, prepaid eSIMs from providers like Airalo are available but not cheaper than local plans for heavy data.

The catch: One NZ’s unlimited plan, while not the cheapest, avoids the steep post-throttle drop seen on Spark’s Endless plans.

What are the downsides of unlimited data plans?

Throttling after data cap

Most NZ “unlimited” plans throttle to 1Mbps after a certain data threshold. Glimp reports that Spark and 2degrees drop to 1Mbps after 40GB (Glimp NZ). One NZ’s Endless plans throttle similarly. Mighty Mobile avoids data caps but imposes a permanent speed ceiling. In all cases, “unlimited” does not mean full-speed unlimited.

Network congestion

During peak hours, even unlimited plans may be deprioritized. This means that if the tower is busy, unlimited plan users may get slower speeds than those on premium postpaid plans (Glimp NZ). This is especially noticeable on Mighty Mobile, which uses Spark’s network and is an MVNO — deprioritization can occur.

Price vs limited data plans

For light users, unlimited plans are often overpriced. MoneyHub’s comparison shows that low-usage users are better off with a limited-data plan ($25–30 for 3–6GB) than paying $30+ for unlimited that they won’t use (MoneyHub). The real value of unlimited plans kicks in when you consistently use more than 30–40GB per month.

What this means: unlimited plans are a win only for those who regularly exceed 30GB; for lighter users, a smaller plan is cheaper.

Which SIM card is best for unlimited data in New Zealand?

eSIM vs physical SIM

Spark and One NZ both offer eSIM and physical SIM options. Mighty Mobile currently provides physical SIMs only. eSIM is convenient for travelers with compatible phones, but for residents, a physical SIM is fine. Glimp confirms that all major providers offer physical SIMs, and eSIM is available from Spark and One NZ (Glimp NZ).

Network compatibility

Mighty Mobile runs on Spark’s network, so coverage matches Spark’s excellent urban and moderate rural coverage. One NZ has its own network with strong 4G/5G coverage. For unlimited data, choose the network with the best coverage where you live and work. MoneyHub’s comparison covers all major networks (MoneyHub).

Best SIM for travelers vs residents

For travelers, prepaid eSIMs from Airalo or local prepaid plans (Spark, One NZ) offer flexibility but are more expensive per GB. For residents with heavy data needs, a postpaid unlimited plan from Mighty Mobile or Spark is more cost-effective. For residents who only need data occasionally, a prepaid plan from Skinny ($25 for 3.5GB) may be cheaper (MoneyHub).

The pattern: the best SIM depends on your length of stay and data appetite; for heavy residents, Mighty Mobile’s postpaid SIM offers the lowest total cost.

Comparison table: cheapest unlimited plans

Three unlimited plans, one clear pattern: the cheapest comes with a speed ceiling, while the others throttle after a data tier.

Pros and cons of unlimited data plans

Steps to get the cheapest unlimited data plan

1. Assess your usage: Check your current monthly data usage. If you use more than 30GB, unlimited starts making sense.
2. Choose a provider: For the cheapest price, pick Mighty Mobile. For better speeds when under the cap, consider Spark or One NZ.
3. Check coverage: Use each provider’s coverage map (Spark and One NZ have strong urban coverage; Mighty Mobile uses Spark network).
4. Compare plans: Use comparison sites like MoneyHub (NZ consumer finance comparison) or Glimp (NZ mobile plan comparison platform) to see all options.
5. Sign up: Order a SIM or eSIM online or in-store. For Mighty Mobile, membership may be required (check MoneyHub details).
6. Port your number: If switching, request a port from your current provider. This usually takes 1-2 days.
7. Monitor your first month: Test actual speeds in your area and ensure the plan meets your needs.

Clarity: What’s confirmed, what’s not

Confirmed facts

• Mighty Mobile offers unlimited data at up to 50Mbps for $29.10/month (member price) (MoneyHub)
• Spark Endless plans throttle after reaching the chosen data tier (Spark NZ)
• One NZ Pay Monthly includes Endless and Unlimited tiers with hotspot allowances (One NZ)
• 21 unlimited-data plans start from $30/month in NZ (Glimp NZ)
• Spark’s Endless price will rise by $3/month on 31 July 2026 (Spark NZ)

What remains unclear

• Whether One NZ’s Unlimited plan has a specific fair usage cap that triggers throttle
• The exact price of 2degrees’ unlimited plan (not disclosed in provided sources)
• How network congestion affects speeds on Mighty Mobile (which uses Spark’s network)

What the providers say

“Spark’s Endless plans give you peace of mind with unlimited data – you’ll never pay extra, just slower speeds after your chosen data tier.”

Spark NZ (official provider)

“One NZ’s Unlimited plan includes 10GB of hotspot data and full-speed data until fair-use limits. After that, speeds are managed to keep everyone connected.”

One NZ (official provider)

“Mighty Mobile’s Fast plan delivers unlimited data at capped speeds – no surprise throttling, just consistent performance for a low monthly price.”

MoneyHub (citing Mighty Mobile plan details)

Final takeaway

Every NZ unlimited plan hides a trade-off behind the marketing. Mighty Mobile’s $29.10 plan is genuinely cheap but slows you down all month. Spark and One NZ offer faster speeds up to a cap, then drop to near-dial-up. For anyone using more than 30GB a month, the decision isn’t about whether to get unlimited – it’s about which kind of “limited” you can tolerate. For a heavy user who streams standard-definition video and doesn’t need lightning-fast downloads, Mighty Mobile’s capped unlimited is the smartest value in 2026. For those who need full-speed access for work or HD streaming, paying $65 for Spark’s 75GB might be worth the premium, as long as you’re okay with 1Mbps after the cap. The pattern: cheap unlimited in NZ is a speed cap, not a data cap. The takeaway for heavy users: if you can live with capped speeds, Mighty Mobile saves you money; if you need bursts, accept the premium.

Related reading: Unlimited data mobile plans in New Zealand · Compare mobile plans in New Zealand

For a broader view of the market, including network coverage and additional providers, see our comparison of NZ unlimited data plans.

Frequently asked questions