You might not think about it often, but every time you pay a bill or receive a salary in New Zealand, a tiny string of numbers makes sure the money lands in the right account. At the front of that string is a two-digit bank code that identifies which bank holds the account.

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New Zealand bank code for ASB: 12 ·
ASB branch number range: 3000–3999 ·
Total digits in NZ bank account number: 16 ·
Prefixes assigned to ASB: 12 and 24 ·
Number of banks in NZ bank code register: over 20

Quick snapshot

1What is bank code 12?
2ASB branch numbers
3Reading an account number
4Timeline signal
  • No recent timeline changes
  • Code 12 has been ASB for decades
  • Check register for any updates

Five facts from the official register, one pattern: each piece of the ASB account number serves a specific routing purpose, from identifying the bank to separating product types.

Label Value
Bank code for ASB 12
Alternative ASB prefix 24
Branch number range 3000–3999
Total account digits 16
Official register maintainer Payments NZ
The upshot

The two-digit code 12 is the most common ASB prefix, but the less-used code 24 also exists for ASB accounts. For anyone sending money, using either 12 or 24 will reach ASB — but getting the branch number right is what ensures it lands in the correct branch-held account.

What bank is 12 in NZ?

Bank code 12 is assigned exclusively to ASB Bank in New Zealand’s payment system, according to the bank’s official help page (ASB official bank help). No other New Zealand bank uses prefix 12.

ASB Bank is the only institution using code 12

  • ASB’s bank code in New Zealand account numbers is 12 (ASB official bank help).
  • The New Zealand bank-prefix directory lists ASB as bank code 12 with a branch range of 3000–3999 (MoneyHub NZ personal finance directory).
  • Other major NZ bank codes: 01 ANZ, 02 BNZ, 03 Westpac, 38 Kiwibank (Wikipedia public reference).

The implication: if you see an account number starting with 12 in New Zealand, you know immediately the bank is ASB. No other institution uses that prefix.

Branch range 3000–3999

ASB branch numbers fall between 3000 and 3999, as confirmed by multiple sources including the official ASB help page and a widely cited summary of NZ bank prefixes (ASB official bank help; MoneyHub NZ personal finance directory). Some branch codes within this range include 3094 for Wellsford and 3425 for an Auckland branch (New Zealand Bank Codes branch lookup site; Gfinco bank directory).

The catch

Not every number between 3000 and 3999 is active. The range is the allocated block, not a guarantee that all 999 numbers are in use. If you need a specific ASB branch code, the safest approach is to check the official register maintained by Payments NZ or look at your own bank statement.

What do all the numbers on my ASB Bank account mean?

New Zealand bank account numbers use a standard format with a 2-digit bank code, 4-digit branch number, 7-digit account number, and 2- or 3-digit suffix (Infor payments documentation). For ASB accounts, the first two digits are always 12 or 24 (ASB official bank help).

Format: 2-digit bank code, 4-digit branch, 7-digit account, 2-3 suffix digits

ASB describes the breakdown this way: the first two digits identify the bank, the next four digits identify the branch where the account is held, the next seven digits are the unique account number, and the final suffix identifies the product or account type (ASB official bank help). The common presentation of NZ bank account numbers is BB-bbbb-AAAAAAA-SSS (Wikipedia public reference).

What to watch

Payments and banking references often describe the bank-branch portion as a six-digit clearing code made of the bank and branch digits combined (Infor payments documentation). That means 12 plus 3094 becomes 123094 as the full clearing code for ASB Wellsford.

Example breakdown

Take the account number 12-3094-0123456-00:

  • 12 = bank code for ASB
  • 3094 = ASB Wellsford branch number
  • 0123456 = unique account number (7 digits)
  • 00 = suffix indicating the product type

This total of 16 digits fits the standard NZ format, with the branch number sitting within the 3000–3999 range (ASB official bank help; MoneyHub NZ personal finance directory).

Why this matters: when you see an ASB account number, you can decode which branch holds it and what product type it is — useful for checking deposit destinations or confirming account details.

Which NZ bank code starts with 12?

Only ASB Bank uses the prefix 12 in New Zealand (ASB official bank help; MoneyHub NZ personal finance directory). This exclusivity makes account identification straightforward for anyone processing electronic payments.

Only ASB Bank

  • Code 12 belongs solely to ASB (ASB official bank help).
  • No other New Zealand bank uses prefix 12 (MoneyHub NZ personal finance directory).
  • ASB also uses prefix 24 for some accounts, though 12 is more common (Wise international payment guide).

Other major NZ bank codes: 01 ANZ, 02 BNZ, 03 Westpac, 38 Kiwibank

For context:

KiwiBank’s public account-number guidance confirms its own bank code is 38 and its branch range is 9000–9499, which is consistent with the same NZ format used by ASB (Kiwibank official account guidance).

The pattern: each bank gets a unique two-digit code, and the first two digits of any NZ bank account number tell you the bank without needing to look up the full branch or account details.

How do I identify an ASB Bank account number?

Look for the prefix 12 or 24 and a branch number between 3001 and 3999. The branch number sits at positions 3 through 6 of the full 16-digit account number.

Look for prefix 12 or 24

  • ASB accounts may use prefix 12 or 24 (ASB official bank help; Wise international payment guide).
  • Code 12 is the primary and most commonly seen prefix.
  • Code 24 is reportedly used for certain older or legacy accounts.

Branch number between 3001 and 3999

  • Branch range 3000–3999 is widely cited (MoneyHub NZ personal finance directory; Wikipedia public reference).
  • Some sources suggest a slightly different range of 3001–4340 (Wise international payment guide).
  • For most practical purposes, a branch number starting with 3 signals an ASB branch.

The trade-off: the exact branch range has minor variation across sources, so if you need certainty, check the register directly rather than relying on a third-party list. For everyday transfers, any number starting with 3 after code 12 is safe.

What is the New Zealand bank branch code format?

The six-digit branch code in New Zealand combines the two-digit bank code and the four-digit branch number. Payments and banking references often call this the National Clearing Code (Infor payments documentation).

Six-digit branch number (bank + branch)

Bank code is first two digits

  • A generic NZ bank-code guide says the first two digits identify the bank and the next four digits identify the branch location (Remitly international transfer guide).
  • ASB’s help page frames the branch number as the branch where the account is held (ASB official bank help).
  • For ASB savings accounts, the suffix code range is 50 to 60 (ASB official bank help).
Why this matters

A generic NZ bank-code guide says the first two digits identify the bank and the next four digits identify the branch location — and ASB explains that different products have different suffixes to keep them separate from each other (Remitly international transfer guide; ASB official bank help).

Step-by-step: How to verify an ASB Bank account number

Here’s a practical way to check whether an account number belongs to ASB and whether it’s formatted correctly.

  1. Count the digits. The full number should be 16 digits total. If it’s shorter, check whether a leading zero was omitted from the suffix (Wikipedia public reference).
  2. Look at the first two digits. If they are 12 or 24, the account is at ASB (ASB official bank help).
  3. Check the next four digits. They should be between 3000 and 3999 for ASB (MoneyHub NZ personal finance directory).
  4. Verify the suffix. For savings accounts, suffixes 50–60 are common. For everyday accounts, suffixes like 00 or 01 are typical (ASB official bank help).
  5. Test with a small amount first. If you’re sending money to a new ASB account, send a small amount first to confirm the number is correct.

For anyone setting up a payment to an ASB account in New Zealand, the actionable step is: confirm the prefix is 12 or 24, and the branch digits fall within the 3000s range — then the transfer will route correctly.

Bottom line: Bank code 12 is ASB Bank in New Zealand, assigned exclusively by the Payments NZ register. For New Zealanders sending domestic transfers: the two-digit prefix 12 or 24 plus a branch number in the 3000–3999 range guarantees the payment reaches ASB. For anyone checking an ASB account number: count 16 digits, decode the bank branch from positions 3–6, and verify the suffix for the product type.

Confirmed facts

  • Bank code 12 is ASB Bank (ASB official bank help)
  • Branch range is 3000–3999 (MoneyHub NZ personal finance directory)
  • Prefix 24 also used for ASB (Wise international payment guide)
  • NZ account numbers use 16 digits total (Infor payments documentation)
  • ASB suffix 50–60 for savings accounts (ASB official bank help)

What’s unclear

  • Exact reason for dual prefix 12 and 24
  • Future changes to branch range
  • Whether the complete branch range 3000–3999 is fully active

The official register of New Zealand bank branch numbers and codes is maintained by Payments NZ, the organisation that operates the country’s payment systems. Their register is the authoritative source for bank codes, branch numbers, and routing information.

Payments NZ Bank Branch Register (payments regulator)

New Zealand bank account numbers follow a standard format: a two-digit bank code, followed by a four-digit branch number, a seven-digit account number, and a two- or three-digit suffix. This format applies to all registered banks, including ASB.

Wikipedia (New Zealand bank account number) (public reference)

Bottom line: For anyone managing payments to ASB accounts in New Zealand, the two-digit bank code 12 is the key identifier. NZ account holders: verify prefix 12 or 24 and branch digits in the 3000s. Payment senders: using the correct six-digit clearing code ensures the money reaches the right ASB branch.
Additional sources

moneybren.com, groups.google.com, bank.codes

For comparison, Kiwibanks bank code 38 follows a similar format for identifying accounts at that institution.

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Frequently asked questions

What is the difference between bank code 12 and bank code 24?

Both codes belong to ASB Bank. Code 12 is the primary prefix used for most ASB accounts. Code 24 appears to be used for certain older or legacy accounts, but ASB’s official help page does not explicitly explain the distinction between the two.

Can I use bank code 12 for all ASB transactions?

Yes, for most ASB accounts, code 12 is the correct prefix. If you are uncertain, check a bank statement or online banking screen for the full account number — the first two digits will show either 12 or 24.

How do I find my ASB branch number?

Your ASB branch number appears as the four digits after the bank code on any bank statement, online banking account page, or deposit slip. For example, in account number 12-3094-0123456-00, the branch number is 3094.

What happens if I use the wrong bank code?

Using an incorrect bank code may cause the payment to be rejected or, in rare cases, sent to a different bank. Always double-check the first two digits before submitting a transfer.

Are all branch numbers between 3000 and 3999 active?

Not necessarily. While the allocated range for ASB is 3000–3999, not every number within that range is assigned to an active branch. If you need a specific branch code, check the official register or your account statement.

Does bank code 12 work for international transfers?

For international transfers to New Zealand, you typically need the SWIFT/BIC code for ASB (ASBBNZ2A) in addition to the bank code and account number. The bank code 12 is part of the domestic account routing and may not be required for international payments.

What is the full format of a New Zealand bank account number?

The standard NZ bank account number format is BB-bbbb-AAAAAAA-SSS, where BB is the two-digit bank code, bbbb is the four-digit branch number, AAAAAAA is the seven-digit account number, and SSS is the two- or three-digit suffix (Wikipedia public reference).

For New Zealanders managing their own ASB account, the key takeaway is: the two-digit code 12 on any ASB account is not random — it’s the bank’s official identifier. For payment senders in New Zealand, using the correct clearing code (12 plus the four-digit branch) ensures the transfer routes correctly. And for anyone checking an ASB account number, the 16-digit format with code 12 or 24 at the front and a 3000s branch number is how the New Zealand payment system recognizes ASB Bank.