Multi-currency budgeting: which rate to budget at when the salary is in dirhams

A budget line reading “family transfer: AED 2,000” is not a budget line. It is a guess about an exchange rate wearing a dirham costume. The amount that has to arrive is fixed in the other currency. What varies is how many dirhams it takes to get there, and a budget built on today’s rate quietly assumes today’s rate is permanent.

At the trading company where I work, nobody quotes a foreign-currency price at spot. When a price is agreed now and settles in ninety days, the quote is built on a rate deliberately worse than the market’s, and the difference is not profit. It is the room the quote needs to survive a move. If the rate holds, the buffer stays in the business. If it moves, the quote still works. Household budgets almost never do this. They take a rate from a search result on the day the budget is written, then treat every later variance as overspending.

Half the currencies a dirham earner deals with have no rate risk at all

The dirham has been pegged to the US dollar since 1997 at 3.6725, and the Central Bank of the UAE holds it there mechanically, intervening at 3.672 when buying dollars and 3.673 when selling. That band is a tenth of a fils wide.

The practical consequence is bigger than it sounds. A dollar obligation is a dirham obligation. A USD 300 annual subscription costs AED 1,102 this year, next year and the year after, before any bank fee. The same applies across most of the Gulf: the Saudi riyal, Qatari riyal, Omani rial and Bahraini dinar are all pegged to the dollar too, which makes them effectively fixed against the dirham as well.

So the first step is subtraction, not forecasting.

Sort the foreign obligations into pegged and floating. Only the floating half needs a budget rate.

How to pick a budget rate that is not today’s rate

For the floating half, convert each obligation at the current rate to find the true cost, then add a buffer of about 5% and budget that number instead.

If a fixed transfer costs AED 2,000 at today’s rate, the budget line reads AED 2,100. In the months the rate is kind, AED 100 accumulates. In the months it is not, the buffer absorbs the difference and the budget does not have to be rewritten. Over a year that is AED 1,200 held back against roughly the size of one bad quarter.

The 5% is not a forecast, and nobody should pretend it is. It is a rounding of ordinary annual movement for a floating currency measured against a dollar-pegged one. A currency that moves 10% in a year breaks through it, and the correct response then is to reset the budget rate at the next review, not to call the month a failure. Twice a year is often enough to review. Monthly re-rating turns a budget into a trading screen.

The rate on the screen is not the rate on the statement

Card spending abroad carries its own layer. UAE banks raised the international transaction fee to 3.14% of the transaction amount from 22 September 2025, up from 2.09%, as Gulf News reported when the change was announced. Industry coverage put the split at roughly 1% to the card network and 2.14% to the bank. On AED 5,000 of spending abroad, that is about AED 157 that never appears in the mid-market rate anyone checks before travelling.

Then there is the prompt at a foreign terminal offering to charge in dirhams. Accepting it hands the conversion to the merchant’s processor at a margin of its own, layered on top of the bank’s. Banks and processors are entitled to charge for converting money, and the fees are published. What breaks budgets is timing: the cost is invisible at the moment of spending and surfaces later as a dirham figure slightly larger than the one remembered.

A worked example in AED

Illustrative figures for one household, using a 5% buffer on floating currencies only:

The gap is AED 218 a month, AED 2,616 a year. On a salary of AED 18,000 that is 1.2% of gross income bought as insurance against a variable nobody in the household controls. The dollar line takes no buffer, because the peg already provides one.

Statements in two currencies do not reconcile against a single-currency budget, which is the reason Masrofna keeps the original currency on the transaction rather than storing only the converted dirham figure.

The habit worth keeping is small. Write down which rate the budget was built on, and the date. A budget that records its own assumptions can be corrected. One that hides them behind a dirham number just looks wrong every few months, for reasons nobody can reconstruct.