IRD have advised that from 1 October 2020, your tax payments will only be accepted at Westpac Bank if you have a barcode.  This is to ensure that the payment goes to the right place.  This applies if you are making a payment at the branch or using one of their Smart ATM’s.
The barcode would usually be printed on the Inland Revenue returns, statements or letters.  A barcode can also be generated on the IRD website and can then be printed or shown on a mobile device.  To generate a barcode, go to www.ird.govt.nz/barcode

Remember alternate payment methods are still available:

• Online banking – pay through your online banking account
• myIR – direct debit and card payments can be made securely online through myIR
• Credit or Debit card via the IRD website – go to the website and search “Make a payment” and select “Pay using credit or debit card”
• Self-service phone line – this phone line operates 24/7
• Automatic Payments – this allows for two signatories and can be used for regular, reoccurring payments such as debt or arrears.  You’ll need to check with your bank as payment processing times can vary.  For instructions, visit the IRD website and search for the form IR586.

See below for more details on how to pay:

https://www.ird.govt.nz/managing-my-tax/make-a-payment/ways-of-paying/paying-electronically