This is a fairly simple approach, but I have a couple of different cards (including ATM/debit and credit) from different banks (which also helps with ATM compatibility issues). When I travel, I take care not to keep them all in the same place. This takes some effort to ensure they're being stored securely and don't get lost, since you're moving them around more than normal. Unless I'm the victim of a serious robbery in which everything is taken, I have an backup option if anything goes wrong.

For example, I might take a card out of my wallet and leave it in a safe at my accommodations. If pickpockets are a concern, besides taking the usual precautions (which could be anything from putting my usual wallet in my front pocket to a travel wallet on a chain to a body-worn hidden pouch), I sometimes move a card to a different part of my body or bag.

If you're doing this with ATM/debit cards, you don't necessarily need to keep a lot of money in the second account, just enough to last you for a few days until you can complete a transfer in an emergency. At least with US banks, a savings account with a lowish balance is one way to accomplish this; there usually aren't any monthly fees (though the interest is generally near-zero), and while there's a monthly transaction limit, it's sufficient for at least a few withdrawals a month.

Consider opening a second account at the same bank. Get an ATM/debit card for the second account. Carry both cards: i.e., duplicate your current setup. The cost to you is whatever the bank charges to open or maintain the additional account, plus the lost interest on the money the second account. But it'll give you a second well from which to draw water.

If you have a friend with a mailbox in Europe, you can open an account with Revolut. You can also wait for the official launch in Australia, which is scheduled for March 2019. Revolut solves your problem by allowing an unlimited number of issued debit cards and by also letting you instantly order a new card to any address in the world. In addition, it has the following benefits for travel:

• It is extremely easy to lock/unlock cards, as it's done directly from their app
• Revolut doesn't charge commission on international currency conversion, unlike normal banks which charge around 2% for each foreign transaction that you make
• You can top it up through any other bank card, so you could for example ask a friend to top it up in case of an emergency
• You can tie your Revolut profile to a virtual phone number from a service like Anveo, which means you could access your account even if your smartphone is stolen along with the SIM card inside it.

If you are in New Zealand, Kiwibank's Loaded for Travel card might provide part of what you are looking for: it carries (some) overseas currencies natively (i.e. you load it in foreign currencies, using the exchange rate at time of load), and they give you two cards linked to the same account (you can disable one if you lose it by calling them or using the website).

From the website:

You get two Loaded™ for Travel cards – one for general use and another as a back-up.

Anecdotally, I found the web interface for loading cards to be a little difficult to use (luckily it integrates well with Kiwibank online banking so I didn't need to use the Loaded for Travel site too much, you really only need it to register your cards initially and to transfer money between different foreign currencies on the card).

You do have to live in New Zealand to register, though:

Loaded™ for Travel cards are only available for purchase by persons in New Zealand and are not offered to any person outside New Zealand (and by purchasing a Loaded™ for Travel card you represent to us that you are in New Zealand and not outside New Zealand).

Maybe if your bank has a mobile/cell-phone app that allows you to tie your credit card/debit card to it and use it instead of carrying your real cards (basically you will still have your real cards to act as a "backup" if your phone is lost.

I sat on my CC a while back, so it literally snapped and broke the chip and pin, but my phone was more than happy to cover the period while waiting for the new card.

I agree with other answers that the best option is to get a secondary payment card from another bank or service.

However, when you lose your card(s) it's unfortunately sometimes the case that a card was lost in a purse or bag that also contained other important items. In some disaster scenarios, travelers lose not only their cards, but also their phone, ID, etc. This answer deals with how to mitigate the adverse effects of even such disasters.

When you lose absolutely everything

Western Union

Western Union allows you to receive up to 1000 USD, even in the case you lose your passport. The money is collected using a secret password given to you by the sender. Before your journey you could ask a trusted friend or family member if they would be willing to do that for you should you find yourself in such a situation. It is easier if you have talked to them in advance and made sure that they know how to use WU, minimising the time needed during an emergency. This means that you have a last resort in a total emergency when you lose absolutely everything. WU offices/agents are found all over the world, even in small towns in remote areas. The main inconvenience of this approach is that if you do not have identification, WU demands that you report loss of ID to the local police before receiving money in such a way. However, in a total emergency, that may be less inconvenient than other options. Also, it is important that your friend/relative verifies that it is actually you before sending, as claiming to be a loved one in distress is a common scam method.

While I was backpacking in challenging areas I always used to have a 2000 rupee note (25 EUR) hidden in my shoe, just in case of disaster or anything and I needed to access the internet, get a taxi, or anything like that. This has the additional benefit of helping you out when there are no working ATMs nearby, or when the internet is down in your area.

Cryptocurrency

Some countries have Bitcoin ATMs. In places with no such ATMs, you may possibly find someone willing to trade cryptocurrency for cash. For emergencies, you could keep some bitcoin in case you lose everything. You could keep the secret key to this bitcoin in the cloud somewhere, encrypted with a password that you have memorised. You can also print the secret key (use a cipher for safety) and keep it with you. Many Bitcoin ATMs require a smartphone to withdraw money, so in case you lose absolutely everything, you may need to borrow a smartphone, or print a QR code at an internet cafe.

Can you get multiple pre-paid Visa or MasterCard? I know Spain and USA have them. Most of them have a small activation fee but some of them have no other fees. You add funds to them online from your bank card, but you don’t have to carry the original bank card with you. They function like a debit card.

If you're going to be somewhere that long, you should really set up local banking there. Come to it, you really are living there so you should make sure to line up all the formalities - ID, healthcare, etc. I assume you are doing this legit, and not absconding on your visa.

Regardless, consider using a PMB for your mailing needs. This is a Private Mail Box. You have your normal mail sent to the PMB. When you're in your home dountry, you stop by once a week and pick up your mail. This also ends all possibility of mail theft, by the way. When you travel, you can ask them to forward your mail anywhere around the world, they will throw it in a "Next Day Air" envelope and off it goes. Most of them are franchises of The UPS Store, so they can ship UPS, but they can also ship FedEx.

So when I need something like that, I just call them every few days to see if they received the mail, and if they did, I ask them to forward my mail. Works slick as a whistle.

If your bank allows You can register the card with Android Pay or similar mobile payment service. I was able to use my mobile as quick wireless payment method even when I left my wallet on a bus. Make sure Your mobile phone supports NFC. ( near field communication ) This does not solve the problem fully but quick wireless payments are much faster this way as some advert of that service says: 'you already have your mobile in your hand'. Additionally for a security measure you don't have to expose your wallet in public.

Everyone's addressed the lost/stolen card, but nobody's talked about the expiration issue, so I'll do so.

If you're going to be gone long enough that you're concerned about a card expiring, check the expiration date before you leave. If it will expire during your trip, contact your bank and see if they'll just issue you a new one now (general advice - I see you've already tried that).

If the bank can't/won't just issue you a new card early, call the number on the back of the card and report it lost/stolen. They'll cancel the card immediately and issue you a new one which should be good for several more years and should more than cover your long trip.

Of course, you'll only want to do this with one card at a time so you have one to live on for the week or two it takes for them to send you a new card. Once you got the new one up and running (and tested), call about the next card.

It's quite stupid to have to jump through this hoop, but if the bank refuses to work with you, they leave no other option.

Consider ordering a Revolut card (or Monese or Monzo, depending what is available in your home country).

Later edit: Revolut provides a prepaid debit card (Mastercard or Visa) with low or zero fees for most operations, which can be used for transactions in foreign currencies at a good exchange rate (better than the usual Mastercard/Visa exchange rates). The free plan allows limited cash withdrawals and the good exchange rate applies with some limits (such as 5000$/month), but there is no monthly/yearly fee and the topups can be made with zero cost from another card. There is a fee associated to the card delivery, but this is waived during periodic promotions.

This isn't just a problem when travelling - a few years ago one bank in the UK had major issues where no one could get cash out for a few days, from what I recall. (my memory might be flaky, I wasn't affected)

• What would you do if your bank's systems crashed and you couldn't get cash out?
• What if your card's pin got locked out and they weren't answering the phone?
• What if the country you were in had some reason they couldn't make calls out?

Get redundant bank accounts from multiple banks, so if the worst happens you can at least rely on another bank to keep running (maybe keep a small amount in each of these banks?)

A few additional techniques:

• Before leaving, try to send Western Union via the website using your debit card. I've never gotten it to work, but if it does work with your card, then just having the card number saved should allow you to WU yourself money from your account even if the physical card is lost.

• Link PayPal to your bank account (or just your debit card) and have someone local you can send money to via PayPal who can convert it to cash.

• If available in your country, get a PayPal debit card linked to your account. Last time I used it, you could configure whether you want it to automatically draw from your funding sources when used, or whether you need to manually load money via the PayPal site.

Where are you travelling to? Depending on how advanced the infrastructure is, you may get some benefit from setting your phone up for contactless payments. Some banks (Monzo that I know of) allow you to remove the normal small payment cap.

I got caught without my bags and wallet in Europe and was able to use my phone to pay my way until I recovered them.

If you're going to assume loss of all possessions, it gets tricky. Depending on how much you're moving about, it may be worth identifying "safe" places to leave small caches. I've used safety deposit boxes for this purpose before, as well as lawyers.

It all depends on how much effort you're willing to go to and how much delay you're willing to endure getting a replacement.

One simple workaround not already mentioned here; request multiple authorized user cards for 'family members'. If the bank does not require a SSN for the authorized user, then just request an authorized user card under your name (because after all, you could have a child by the same name as you). If thats not an option, then use real family members. While the name of the card wont be yours, in the vast majority of cases you wont need it to be. For the few times it matters (i.e. you think somebody maybe manually checking the name on your card against your id) just use cash. ATMs don't care what name is on a debit card (just be sure you set the pin before you leave).

Another workaround not yet mentioned: you can open several checking accounts in the same bank (and instantly move money between them). Each checking account will have a different debet card tied with this account. This way you can keep the bulk of money on the bigger account, which debet card you'd only use as last resort, and routinely use the card linked with other account, where you keep $500 and top it up periodically.