Great question. There are a few considerations:
- Cards that will provide best points return, and Personal vs Business cards for large volume of Business expenses
- Banks / cards that your accountants are most happy to work with
- Tax deductibility of annual fees
- Effective points earn for ATO spend
On 1, some banks have been known to exclude large volumes of Business expenses being run through personal cards as being appropriate within their terms and conditions. Accounts have been shut down (ANZ comes to mind as one who were in the news recently). Given your work expense volume you probably want to be sure you’re going for an appropriate card.
That said many business cards are assessed and issued under the name of the account holder, not the business. In terms of options, have a look at the Business Cards section at the bottom of the page here.
On 2., obviously check with your accountants as well, but I am finding that mine don’t mind which kind of credit card I put my expenses on and are happy to work with me for the right card for the right means. Yours might prefer a specific set up, I don’t know. Not that should dictate how you run your finances but it’s still a consideration if it adds admin overhead.
On 3., this matters most for the high annual fee cards out there - my understanding is that fees are tax deductible only for when the card is used exclusively for business expenses.
On 4., this is a topic that is ever changing as ATO earn has been reduced a lot in the last 6-12 months. There are very few cards left which allow points earn with ATO, especially uncapped. How a bank would determine if a personal card was being used for business ATO spend I don’t know, given you can do personal ATO spend as well, but I guess that would be based on volume.Anyway, some info on cards which currently pay out or not on ATO can be found here.