For tax purposes the IRD requires that all deductions against your income are backed up with source documents such as invoices, receipts and statements.
Can I just keep bank statements?
While this shows actual expenditure, theres no evidence it should be deductible. You still need to keep a receipt or invoice to show what the expenditure was for.
It’s advisable to keep all receipts and invoices when you incur business expenditure.
Receipts under $50?
Receipts for purchases under $50 aren't needed to claim GST on expenses, but are still needed to back up expenditure for income tax purposes.
What about home office costs?
If you are operating an office out of home you should keep invoices & receipts for expenses that form part of your home office claim. These include rent agreements, mortgage statements, rates invoices and telephone bills.
Can you keep electronic copies?
Yes you can - hooray for technology! Just snap a picture, or scan and save to Dropbox, Evernote or Google Docs to have a copy forever in case you need to show the IRD.
If you have any other questions please get in touch!