Summary: Unless travelling overseas, you should only use debit cards rather than credit cards unless you are so disciplined you never pay interest or fees, or spend more money than you otherwise would. For most people, the few benefits of some credit cards are outweighed by the fees, interest and overspending traps they fall into.

However, for the disciplined minority, there are some worthwhile opportunities to exploit with credit cards. One of these is the free "cashback" money often available for obtaining a new credit card and spending a minimum amount in the first few months. If you limit this to just the cards with no annual fee in the first year, and cancel the card before the second year commences, you can get up to $200 of free money for little effort.

Personally, I don't waste my time with unnecessary credit cards; but in order to quantify the time and effort required to harvest this kind of free money, I have done so once with the best available credit card cashback opportunity currently: the ANZ Platinum Credit Card - $200 cashback if you spend $500 on the card in the first 3 months.

Gain: ~$200 per card.

Time: ~3 hours to apply, submit ID documents, meet the qualifying criteria, obtain cashback and then cancel.

Details:

1. Search the financial product comparison sites for "Cashback Credit Cards" and identify the ones with the greatest cashback, no annual fee and fewest traps and hurdles

In Australia, a comparison site like Finder.com.au will have a continually-updated page listing most current cashback offers:

finder.com.au - Cashback Credit Cards

I picked the ANZ Platinum Card as it offers:

- A high lump sum cashback amount ($200) that is easy to efficiently obtain and confirm.
- No annual fee for the first year. I will cancel before the second year.
- The qualifying conditions are relatively easy to meet (spend $500 in 3 months).
- There are extra benefits that can be utilised or tried in the first year like free travel insurance


2. Efficiently obtain and activate the card, meet the cashback criteria and cancel at least 2 weeks before the second year commences

- Most of the applicable cards can be applied for online and as long as your credit is good you will be accepted within a day.

- The card will be sent out in the mail within a week

- Card activation for a bank you don't already have an account with requires a branch visit (for ANZ I nominated a CBD branch I will be close to for another regular trip). If you use a bank you already have an account with then activation can be done via the phone

- Efficiently meet the qualifying criteria. You may need to temporarily channel some larger payments via the new credit card. If you have a big payment coming up (e.g. travel, appliance) it's worthwhile aligning the timeframe with card activation.

- Chase up your cashback if not paid promptly. And remember to cancel the card as soon as you have received your cashback as high annual fees often kick in after the first year. Even if they don't, it's not worthwhile keeping most such cards as they are not the best available.

- Ensure you cancel your card at least a few weeks before the second year fees start. I just called up the bank and did it over the phone. However, some banks may request you to confirm in writing. If so, ask for an email address or for them to send out an addressed envelope.
> Finder.com.au - Guide to cancelling your credit card in Australia


3. Results of $200 cashback trial with ANZ Platinum Card

I applied in August 2016 and by August 30th had met the minimum spend condition. I spent just over $500 on online grocery shopping (Woolworths) and alcohol shopping (Dan Murphys). This is shopping we do anyway, so no extra spending was required.

I got my $200 ANZ promotion bonus 63 days later on October 3rd. It was automatic, no extra effort was required:


I will be closing this ANZ credit card before the second year commences and the annual fee applies.

Note I also used online shopping cashback - Cashrewards - for these purchases, which provided $35 extra cashback just for clicking the Woolworths and Dan Murphys links from the Cashrewards site:



4. Results of $250 cashback with Commonwealth Bank Low Rate credit card

The Commonwealth Bank periodically provides a $250 cashback offer for new signups of its Low Rate credit cards (standard or gold). The requirements are simple and you can even meet the $500 minimum spend with tax office payments.

As I had my tax due in October, and am already a customer due to my CommSec share broking account, I decided to exploit this offer too.


One of the appealing things about this offer is that all of the terms and details are clearly laid out:

 The $250 cashback and $0 annual fee for the first year offer applies to new personal Low Rate, Low Rate Gold and Interest Free Days Business Credit Cards (personal liability) applied for online between 10 October 2016 and 31 October 2016 offer only. To be eligible for the $250 cashback, you need to spend $500 on eligible purchases using your new card by 31 December 2016 (includes BPAY transactions, payments to the ATO but excludes balance transfers, cash advances and any purchase or transaction that is subsequently reversed or refunded). Offer excludes applications made in-branch or by telephone, all existing cards, Corporate and Business Liability cards, upgrades and switches from other card types and is not available to customers who currently hold, or have held, any personal Low Rate, Low Rate Gold or Interest Free Days Business (personal liability) credit card in the 12 months prior to 10 October 2016. After the first year, the then current standard annual fee applicable to your card type will apply. 

Offer only available on one CommBank credit card per customer, can be withdrawn at any time at the discretion of the Bank, and cannot be used in conjunction with any other offer. The cash back will be applied to your account within 60 days of you meeting the spend criteria and will appear on your statement as ‘$250 cash back’. You will be ineligible for the cash back if your account is closed, transferred, upgraded or in default at any time prior to the cash back being credited to your account.
CommBank credit cards - $250 cash back

Further Info:

finder.com.au
> Cashback Credit Cards