Forex Card, Cash or Indian Debit Card Abroad: What Each Option Really Costs You

A forex card locks in the exchange rate at the time you load it. If the rupee weakens mid-trip, you are insulated. That is the genuine advantage, and it is real. Banks like HDFC, ICICI, SBI, and Thomas Cook issue multi-currency forex cards that let you load several currencies at once, useful if you are moving between, say, Europe and the UK on the same trip.
The costs come in specific situations. Most forex cards charge a cross-currency fee of 2 to 3.5% when you spend in a currency the card is not loaded with. If you loaded euros but buy something in Swiss francs, that fee applies. ATM withdrawals abroad on a forex card typically attract a flat charge of $2 to 5 per transaction, sometimes more, depending on the issuer. Reloading the card from India also carries a reload fee on some cards. Check whether your card charges an inactivity fee if you leave a balance on it after returning, several do. The forex card wins on rate predictability and on safety (it is not linked to your savings account), but only if you load the right currencies and use it at POS terminals rather than ATMs wherever possible.
Cash has one advantage no card can replicate: it works everywhere. A street vendor in Hanoi, a tuk-tuk driver in Bangkok, a market stall in Marrakech, none of them have a card terminal. In many destinations across Southeast Asia, the Middle East, and parts of Eastern Europe, cash is still the dominant transaction mode.
The cost problem is where you source it. Exchanging rupees at an airport money changer in India before departure typically gives you a rate 2 to 4% worse than the mid-market rate. Exchanging at the destination airport is almost always worse. The better move is to use a reputable forex dealer in your city before you leave, Thomas Cook, BookMyForex, or a local RBI-authorised dealer, where rates are more competitive and you can compare online. Carrying cash also means carrying risk. Travel insurance covers theft in some cases, but not always cash. Keep amounts reasonable: enough for two to three days of spending, not the whole trip.

Most Indian travellers default to their regular SBI, HDFC, Axis, or Kotak debit card when abroad because it is already in their wallet. The convenience is real. The cost is also real and tends to be underestimated.
A standard Indian debit card used abroad typically incurs three separate charges on every transaction. First, the foreign transaction fee: usually 3.5% of the transaction value, charged by the bank. Second, the currency conversion markup: the bank converts at its own rate, which sits 2 to 4% above the mid-market rate. Third, if you withdraw cash from a foreign ATM, there is a flat ATM fee on top of the percentage charges, HDFC charges ₹125 plus taxes per international ATM withdrawal, SBI charges ₹100 plus taxes. On a single ₹10,000 withdrawal, you could be paying ₹600 to 900 in combined charges before you have spent a rupee on the trip itself.

Dynamic Currency Conversion (DCC) makes this worse. When a foreign ATM or POS terminal asks if you want to be charged in Indian rupees rather than the local currency, always decline. Choosing rupees hands the conversion to the foreign bank at a rate that can be 5 to 8% above mid-market. Always pay in the local currency and let your Indian bank do the conversion, it is still expensive, but less so.Across all three options, a few costs sit in the fine print and rarely come up in conversation at the bank branch.
GST applies to foreign exchange transactions in India. The rate is 18% on the fee component (not the full amount), but on a large conversion, this adds up. When you buy forex or load a card, ask for the total all-in cost, not just the exchange rate.

Some forex cards and international debit cards charge a fee simply for checking your balance at a foreign ATM, even if you do not withdraw. This is typically ₹25 to 50 per inquiry but is worth knowing if you are checking balances frequently.
If you are travelling to a country with restricted currency, Japan, for instance, where yen is not freely available in India, you may need to source it at the destination. Airport rates in Tokyo are significantly better than what Indian banks or dealers can offer on yen, so the usual advice to sort your currency before departure does not always hold.
Mark-up rates also change. The rate your bank quotes today on a forex card reload or an international transaction may differ from what it quoted last month. Banks are not obligated to hold a rate stable, and several revise their international fee schedules periodically.The short answer is two of the three, never just one.
A forex card loaded with the primary currency of your destination handles most daily spending, hotels, restaurants, transport apps, retail. It keeps your savings account insulated from international exposure and gives you a locked-in rate. Keep it for POS transactions.
Cash in the local currency, sourced from a reliable dealer before departure, covers the situations where cards fail: markets, small vendors, tips, transit in areas with poor connectivity. Keep it to a manageable amount and store it separately from your cards.
Your Indian debit card stays in your bag as the emergency fallback, for an ATM withdrawal if your forex card is declined or lost, or for a situation where you need rupees converted urgently. Use it as the last option, not the first.
The traveller who carries only a debit card because it is easy pays, on average, 6 to 9% more on every foreign transaction than one who planned their currency mix before boarding. That gap, across a two-week trip, often adds up to a flight upgrade or two extra nights at the hotel.