The Auditor-General says the Inland Revenue Department could make it easier for first-time taxpayers to understand how to pay their tax.
A performance audit has found the department's website difficult to understand and recommends it be redesigned so people can easily find the information they need.
The audit also found taxpayers' success with calling Inland Revenue varied.
Only 11.8% of callers were able to get through on 15 July last year - yet the day before, 88.6% of callers got through.
It's also recommended the IRD monitor the website's effectiveness and review the way call service quality is monitored.
The audit also recommended that help be given to taxpayers who are more likely not to pay their tax, such as tradespeople who are often paid in cash for jobs.