Cash
How to track cash when you're carrying three currencies at once
Card spending tracks itself. Every tap leaves a record with a date, an amount and a merchant, and worst case you can reconstruct a month from a statement. Cash leaves nothing. No notification, no history, no statement to reconcile against — and on a long trip through places where cash still rules, it is often most of what you spend.
Cash is a balance, not a list
The instinct is to track cash the way you track cards: write down each purchase as it happens. That fails within about three days, because you will forget the 20 baht water, the tip, the tuk-tuk, and the coins you handed a kid selling bracelets.
The method that survives contact with an actual trip is the opposite. Track the pool, not the purchases. You know exactly how much cash entered your pocket, because it arrived in a small number of large, memorable events — a withdrawal, an exchange, money you started with. You can count what is left at any moment. Everything between those two numbers is spending, whether or not you wrote it down.
The mistake that breaks every cash budget
An ATM withdrawal is not spending
Taking ฿10,000 out of a machine does not make you ฿10,000 poorer. You moved money from one pocket to another — the bank balance went down, the cash pool went up, and your net worth is unchanged apart from the fee.
Count the withdrawal as an expense and you will double-count everything: once when you withdraw it, and again when you spend it on dinner. Budgets built in spreadsheets get this wrong constantly, and it is why the total always looks worse than reality.
The same applies to changing currency at a border, moving money into a hotel safe, or splitting a stash between your bag and your daypack. None of that is spending. It is the same money in a different place, and a tracker that cannot express that distinction will lie to you all trip.
The only exchange rate that matters is yours
You will never receive the mid-market rate you see on a currency converter. Between the ATM operator's fee, your bank's fee, and the spread built into the rate itself, what you actually got is somewhere below it.
So do not record the published rate. Record the two real numbers — the local currency that came out of the machine, and the amount your bank actually debited — and let the rate be whatever those two imply:
Your effective rate
local currency received ÷ home currency actually debited. If ฿10,000 cost you £232.40 all-in, your rate was 43.03 baht to the pound, no matter what any board in the airport said. Every purchase you make from that pile of cash should be valued at that rate.
Do this and the fees stop being a separate line you have to remember. They are already inside the rate, spread across everything you buy with that cash — which is exactly where they belong.
Count, don't reconstruct
Every few days, count what is actually in your wallet. Compare it to what your tracking says should be there. There will be a difference. There is always a difference.
The instinct is to hunt for it — to sit in a hostel trying to remember what happened to 340 baht. Do not. The time costs more than the money, and you will not find it. Record the gap as a single adjustment and move on. What matters is that your balance is true again from this moment forward, because a cash pool that has silently drifted 2,000 baht out of step is worse than useless — it tells you confidently wrong things for the rest of the trip.
Leftover currency does not disappear at the border
You leave Thailand with ฿1,200 in your bag. That is not spent and it is not gone — it is a holding in a currency you have stopped using. It has three possible futures: you change it (paying the spread a second time), you carry it until you come back, or you write it off.
All three are fine. What is not fine is letting it silently vanish from your accounting, because then the total you spent in Thailand is overstated by ฿1,200 and you will believe Thailand is more expensive than it was. On a multi-country trip these fragments add up to real money across five or six borders.
Keep a wallet and a safe as separate pools
Most people carrying meaningful cash keep some of it away from their person — in a hostel locker, a hotel safe, or the bottom of a rucksack. Treat that as a second pool, not as part of your wallet.
The practical reason is the count. If “my cash” is one number spread across two physical places, you can never verify it without unpacking everything, so you stop verifying, and the drift compounds. Two pools with a transfer between them means the wallet — the one that actually changes every day — can be counted in ten seconds.
What this looks like in practice
Kapunka is built around exactly this model: cash is a pool with a real opening balance, withdrawals and exchanges move money rather than spend it, wallet and safe are tracked separately, and every purchase keeps its original local amount alongside what it was really worth at your rate. You can count your wallet and correct the balance in a few taps, without hunting for the missing 340 baht.
Related
Cash is the invisible half of a travel budget. The visible half has its own trap — cards settle days after you spend, at a rate set on the day they clear. And both sit inside the wider list of costs a budget tends to miss.