Why Excel Is Not Enough to Manage a Currency Exchange

Almost every exchange business that has software today started with Excel at some point. And that was actually the right decision: Excel is free, everyone knows it, and on day one of the business it gets the job done faster than any software.

The problem with Excel is not that it is a bad tool. The problem is that Excel is a calculator with memory, while an exchange business needs an accounting ledger. After a certain point, these two things part ways — and usually nobody notices the exact moment it happens.

How far can Excel take you?

As long as three conditions hold:

Volume is low. 10 to 20 vouchers a day, which one person can still keep in their head until the end of the day.
One person records entries. Meaning two people never open the same file at the same time.
Currencies are limited. Two or three currencies, with no variants (cash, transfer, Tehran, Dubai), and no cross-settlement.

If all three are true, Excel really is enough and you do not need to read this article. But as soon as one of them breaks, the costs begin — and the first thing you lose is “knowing”, not “recording”.

Five places where Excel breaks in an exchange business

1. You do not know your real profit

This is the most important point, and it is exactly where most exchange businesses get it wrong.

In Excel, you usually calculate profit like this: “I sold 10,000 dirhams 5 rials above my purchase rate, so I made 50,000 rials.” This calculation is only correct if you bought those exact dirhams on the same day and at the same rate.

But your dirham balance is a pool: filled from ten different sources at ten different rates. When you sell, you sell from the pool, not from one specific purchase. The real profit of each trade is the difference between the selling rate and the weighted-average cost of your inventory at that moment — a number that is not written anywhere in Excel and changes with every purchase.

We have all seen the result: an exchange business where every single trade was “profitable”, but at month-end there is less money than expected. The money did not go anywhere — the profit was never that high in the first place. The difference was eaten by rate movement on the open inventory (FX position), and Excel does not show it to you because it does not even know what an open position is.

If you cannot say at any moment “how open am I in dirhams right now, and what is my average cost?”, you are not calculating your profit — you are guessing.

2. Operational knowledge lives in one person’s head

An exchange Excel file always has an owner. That person knows what column K means, knows why that row is yellow, knows that “Hassan 2” is different from “Mr. Hassan”, and knows what the hidden sheet is for.

As long as that person is at work, everything runs. The problem starts the day they get sick, go on leave, or leave your company. Only then do you realize the file was not your ledger — it was their personal notes.

3. Two people cannot work at the same time

The common workarounds are all bad: put the file on the network and let it lock; create versions like final-2-revised.xlsx; or have one person manually enter everyone else’s vouchers at the end of the night.

All three lead to the same result: your data is always several hours behind. And in a market where the rate moves within half an hour, making decisions with data from two hours ago means not making decisions at all.

4. There is no Audit Trail

In Excel, any cell can be changed and nobody knows. Not who, not when, not what it was before.

This is not only about misuse — it is more often about mistakes. Someone clicked a cell, typed unintentionally, and saved the file. Three weeks later, when the balance does not reconcile, you have no way to find that moment. You have to read the whole ledger again.

In a real accounting ledger, a posted voucher is corrected, not deleted; and every change has a timestamp and a user. That is the difference between a “ledger” and a “file”.

5. The customer cannot see their statement

The customer calls: “What is my balance?” You open the file, apply filters, sum the rows, and give them a number. The customer says, “I see 300 dollars more.” Now you have to compare two ledgers line by line.

Every time this happens, two things are spent: your time, and the customer’s trust. And trust is the most expensive asset an exchange business has.

The hidden cost: errors that are never found

Excel errors are usually not noisy; they are silent. A few real examples we have seen during migrations:

A SUM formula that missed one row. A new row was added below the SUM range, and the total ignored that item for months.
Copy-pasted relative references. A row was copied, and the rate pointed to the neighboring row, not its own rate.
A number stored as text. The total ignores that item and no error is displayed.
Two customers with the same name. “Mohammadi” and “Mohammadi ” (with an extra space) become two people, and balances are split between them.
Rounding. Rials were totaled with 2 decimal places, and after a thousand vouchers, differences of a few rials became a meaningful number.

None of these gives you a message. One day a balance simply does not reconcile, and you do not know since when.

A simple test: have you outgrown Excel?

Answer these five questions. Each “no” is one point:

If I ask right now how open you are in each currency and what your average cost is, can you answer in less than one minute?
If a customer says “my balance is wrong”, can you send them their statement without opening the file?
If someone recorded a number incorrectly three weeks ago, can you find out who and when?
If the main laptop dies today, do you have yesterday’s data?
Do you know yesterday’s profit without manual calculation?

1 to 2 points: You still have time, but start planning. 3 points and above: Excel is no longer your ledger; it is your risk. The question is no longer “if”. It is “when”.

Migration is not as scary as you think

The biggest reason exchange businesses stay in Excel is not Excel itself — it is fear of migration: “What happens to my ten years of history?”

The right answer is that history must be migrated, not that you start from zero. A proper migration means:

All old vouchers are transferred with their own dates and descriptions, not just today’s balances.
Each customer’s balance in the new system matches the old system rial by rial — and that match is provable, not just claimed.
Every new voucher can refer back to its old voucher, so if a customer asks about last year, you have an answer.

We have done this many times; in our largest recent migration, more than 70,000 vouchers and 23,000 transactions were transferred, and balance verification was fully green. Migration from Excel is usually even simpler, because the Excel structure is simpler than an old database.

Summary

Excel is not a bad tool; it is the wrong tool — exactly like using pliers instead of a wrench. It works, until the day it rounds off the nut.

An exchange business needs three things that Excel does not provide by nature: live FX position, an undeniable double-entry ledger, and simultaneous multi-user access. Until you have these three, you go to sleep every night with a guess.

If you want to see what your exchange ledger looks like in a real system, you do not have to take our word for it — build a dedicated demo with sample data and see for yourself.