If your travel is part business and part holiday (whether in New Zealand or overseas), for tax purposes the IRD look at the dominant purpose of the trip to determine deductibility of expenditure. If the purpose of the trip is principally for business then the travel expenses will be deductible – with the exception of any expenditure relating directly to the personal part of the trip, which will not be deductible.
Conversely, if the purpose of the trip is principally for personal pleasure then the travel expenses will not be deductible – with the exception of costs directly incurred in carrying out business activities. These may include costs incurred in attending meetings or conferences, or meals with customers.
Always keep all of your receipts, which will make processing your business expenses easier and more accurate.