New Zealand has a short code system that confuses a lot of business owners. You’ve seen the ads: “Text PIZZA to 1234 for a discount” or the appointment reminders "Reply YES to confirm your appointment" coming from a short code number, but do you actually understand how it works? When do you need one? And most importantly, which option is right for your business?
This guide breaks it all down, from Built-In Codes to Dedicated Codes to SMS keywords, so you can make the right choice for your situation.
💬 Why Does New Zealand Have Short Codes?
New Zealand regulators require that bulk business messages come from a short code, not a regular mobile number (021, 022, 027). Carriers block messages sent from standard mobile numbers if they detect bulk sending. It’s a compliance and anti-spam measure designed to protect consumers.
Short codes work because they’re:
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Regulated
Only approved businesses can use them, so carriers know where the message is coming from.
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Whitelisted
Short codes are trusted by the network, so your messages get through spam filters reliably.
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Compliant
Short codes support two-way messaging, which is required by New Zealand’s Unsolicited Electronic Messages Act 2007. Customers can opt out by replying STOP.
In short, the system protects consumers while giving legitimate businesses a trusted way to communicate at scale.
⚙️ The Three Main Options: Built-in Codes, SMS Keywords, and Dedicated Codes
You have three choices when you want to send SMS in New Zealand. Each has a different cost, setup time, and use case.
1. Built-in Short Code
A built-in short code is a 3 to 4 digit number allocated to you as part of your SMS plan. It’s shared with other TNZ customers, but everyone’s messages route correctly.
- Cost: Free, included with any TNZ plan.
- Setup time: Immediate.
- Best for: Appointment reminders, order confirmations, password resets and alerts.
- Limitation: You can’t use it for promotional marketing. For marketing messages you need the free-to-text option.
- How it works: The customer receives your message from the short code and has a 5-day window to reply. As long as messages keep being exchanged, the conversation stays active.
2. Dedicated Short Code
A dedicated short code is exclusively yours. No one else uses it, and you own 100% of the traffic hitting that number.
- Setup time: About 4 weeks.
- Best for: Brand protection, promotional messaging and customer-initiated conversations.
- In and Out: You can send and receive messages using your Short Code (the received messages don't have to be a reply).
- Keywords: Unlimited and free once you own the code. A 6-digit code could run “Text INFO to 123456” and “Text OFFER to 123456” at once.
3. SMS Keywords
This is the “text BRANDNAME to 1234” option you see on radio ads. You buy a keyword on a short code, and inbound texts route to you.
- Cost: $200 setup, $100 per month.
- Setup time: About 1 week.
- Best for: Radio campaigns and promotions where customers initiate contact, like “Text PIZZA to 875 for 20% off.”
- Who pays what: The customer texts in and pays standard SMS rates (around 20 cents); you receive it free. If you reply, that’s 10 cents per message and they receive it free.
- Advantage: Cheap compared to a dedicated code, with a memorable short number (3 to 5 digits).
- Limitation: It runs on a use-case specific keyword code. The keyword is what matters, not the number, so if someone else already uses your keyword on that code, there’s a conflict.
📋 Example: Built-in Code
A physiotherapy clinic sends appointment reminders from the built-in code. Patients text back to confirm. Simple, no extra short-code cost, single use-case, no setup.
Dedicated Code Lengths
4-Digit Dedicated Code
- Cost: $600 setup, $299/month.
- Perceived prestige: High. Banks and big brands use these.
- Best for: Large businesses, national campaigns, and cases where brand identity is critical.
6-Digit Dedicated Code
- Cost: $300 setup, $89/month.
- Perceived prestige: Professional, but more accessible.
- Best for: Growing businesses, local operations, and cost-conscious campaigns.
Carriers introduced 6-digit codes to make dedicated codes more affordable. The idea is 4-digit codes for major brands and 6-digit codes for your local business. It’s almost like an extended phone number.
Whichever length you choose, a dedicated code is for any business that wants complete control: brand protection with your own number, the ability to send promotional messages, and the option to let customers start conversations with you.
Can you pick a specific number?
Numbers begin with a 4xx, 5xx or 8xx. Get in touch with the TNZ team if you have a specific number in mind.
📋 Example: Dedicated Code
A national retailer buys a 4-digit code to run a nationwide promotion, for complete control, brand visibility and premium positioning. A regional business buys a 6-digit code as a cost-effective alternative, with the same capabilities, a slightly longer number, and a fraction of the price.
📋 Example: SMS Keyword
A local radio station runs a promotion, “Text SUMMER to 875 to enter the draw.” People text in, and the station receives hundreds of entries and automatically replies with confirmation numbers.
💬 Are Your Messages "Transactional" or "Promotional"?
Nearly every short code choice in New Zealand comes back to one distinction. Is your message transactional or promotional?
Transactional Messages
Appointment reminders, alerts and confirmations. These are messages that deliver essential business information, like an order confirmation, an appointment reminder, a password reset or a bank alert.
- A built-in short code handles it. Access is included with your plan.
- A dedicated code handles it too, if you'd rather have your own number.
- Cost to customer: If they reply, they pay standard SMS rates (around 20 cents).
- Compliance: Automatic. Transactional messages are exempt from heavy opt-out requirements.
Promotional Messages
Marketing, discounts and sales. These are messages designed to sell something or promote an offer, like “Get 20% off this weekend” or “Summer sale starts now.”
- A built-in short code won't send them. These codes are transactional use-cases only.
- A dedicated code with standard billing is not recommended. If a reply costs the customer money, you could face complaints from the recipient and the DIA.
- A dedicated code with free-to-text (FTEU) is the right choice. The customer replies STOP for free, you cover the cost, and you stay compliant.
New Zealand treats promotional messages differently, because the Unsolicited Electronic Messages Act 2007 says marketing has to carry a free, easy opt-out. Free-to-text (FTEU) lets customers reply “STOP” without cost, which is why promotional campaigns need Free-to-Text dedicated code.
🧭 Quick Decision Guide
- Reminders, alerts, confirmations, 2FA: Free to start, live immediately.
- Marketing to your customer list: Dedicated short code with free-to-text.
- You want your own branded number: Dedicated short code, 4-digit or 6-digit.
- Not sure yet? Start with the built-in short codes. It costs nothing, and you can upgrade later without redoing your setup.
🌏 Local or Global Provider?
This is where it pays to look past the brand names you already know. You can technically send NZ SMS through a global platform like Twilio or AWS. The catch is that both are built for the whole planet. Getting access for sending to New Zealand lands back on your to-do list.
🌐 International Provider
You prepare the short code application yourself: service description, sample message content, opt-in and opt-out screenshots, volume forecasts, billing details, emailed to a short-code desk. Then roughly five to six weeks for carrier approval, plus a three-month minimum term, before your first message sends.
✅ TNZ
The New Zealand part is already done. You send on a compliant short code the moment you sign up, we hold the carrier and Department of Internal Affairs relationships, and we prepare any dedicated-code application for you. Billed in NZD, supported in your timezone.
None of that makes these international providers bad platforms. They're just not local, and a short code is a deeply local problem.
⚡ The short version
With a global provider, compliance and provisioning are your problem. With TNZ, they're ours. You start on a compliant short code on signup, so you send today rather than in six weeks.
📋 What This Looks Like in Practice
💆 Example 1: Small Business, Appointment Reminders
A massage therapy clinic sends appointment reminders on a built-in short code. The cost is a $20/month TNZ base plan plus SMS charges, averaging about $5/month for reminders. Totalling around $25/month, with no additional cost for the short code.
🍕 Example 2: Local Restaurant, Promotion
A pizza restaurant runs a radio campaign: “Text PIZZA to 875 for 20% off.” Using an SMS keyword costs $100/month. They get 50 inbound texts a week and reply to each for free from the customer's point of view, adding around $5/month.
🛍️ Example 3: National Retailer, Nationwide Campaign
A national clothing brand launches a customer loyalty programme. They need a dedicated number for brand consistency and want to send promotional SMS to their 10,000 customers, so they buy a 4-digit code. Cost: $600 setup, $299/month, plus SMS charges. At $0.10 per SMS part, sending 10,000 SMS a month comes to $299 (monthly fee) plus $1,000, so $1,299 for the campaign. The cost is worth it for the brand value and delivery reliability.
🏢 Example 4: Growing Agency, Multiple Clients
An agency manages SMS for 50 small clients. Each starts on a built-in code at no extra short-code cost, and as clients grow they upgrade to 6-digit dedicated codes at $300 setup and $89/month each. The agency ends up managing a mix: some on built-in codes, some on 6-digit, some on 4-digit. Each client pays for their own code, while the agency handles the integration and keeps everything simple.
Same country, same rules, four different answers. None of these businesses had to become experts in NZ telco compliance to get there.
🚀 How to Upgrade from Built-in to Dedicated
This is the standard path for most businesses. You start on a built-in code while you test, learn and send messages. After a few weeks, you decide you want your own code, fill out a PDF form, TNZ submits it to the carriers, and about four weeks later your dedicated code is live.
From that point you can send from your dedicated code straight away. All your existing workflows and automations keep working, they just use your new number instead. It’s the smart way to onboard: test cheap, then upgrade when you’re confident.
Need the full pricing breakdown?
Compare setup fees, monthly costs, setup times, built-in codes, use-case specific keywords, 4-digit codes and 6-digit codes in the full guide.
View the Full Short Code Pricing Guide →
❓ Common Questions
Can't I just use my business mobile?
No. NZ carriers and the Department of Internal Affairs block bulk business SMS sent from standard 021, 022, and 027 numbers. A short code is the compliant way to send.
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How soon can I start sending?
On a built-in code with TNZ, straight away. A dedicated code needs carrier approval, which takes a few weeks, but TNZ manages that application for you while you carry on.
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Can I move from a built-in short code to a dedicated one later?
Yes. You start with the built-in route to test and learn, then upgrade when you're ready. Your existing workflows keep running, they just send from your new number.
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Can I use multiple short codes?
Yes. Multiple short codes can be set up on a per Account, SubAccount, Department or even per-User basis.
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Can I get a memorable short code like 123456 or 800800?
Get in touch with the team and we'll see what's possible. Numbers begin with a 4xx, 5xx or 8xx.
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What if I share a keyword with another business on the same short code?
On use-case specific keyword codes, each keyword must be unique. If another business already has PIZZA on 875, you can’t also use PIZZA and would need a different keyword. This is rare in practice, but it’s why keywords are reserved when purchased.
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What happens after 5 days if no one replies to my message?
The 5-day reply window closes, and a later text is treated as a new conversation. In practice, if you send another message to that customer the window resets, so ongoing conversations flow naturally.
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What if I’m sending both transactional and promotional?
Use a dedicated code with free-to-text (FTEU), which covers both. Alternatively, keep the built-in code for transactional messages and a separate keyword or dedicated code for promotional.
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Start Sending Today
Register for a 14-day TNZ free trial and you get 20 SMS credits to test the service immediately. Send a reminder, receive a reply, try an automation and see how the built-in short code works before you commit to a dedicated number or a larger campaign.
When you are ready to compare the full pricing, setup times, SMS keywords, 4-digit codes and 6-digit codes, read Understanding SMS Short Codes.
Register for Your 14-Day Free Trial →