Custody fees, explained in one worked example
“0.5% per year” sounds abstract. So here is a real walkthrough of how the Changer.ae custody bill is actually computed — the same method your monthly statement machine runs.
The method, in five steps
- Snapshot hourly. At the top of every hour during the billing month, the wallet's coin balance is read.
- Convert to USD. That snapshot is multiplied by the market price at that moment — an hourly USD (or AED) value.
- Average the month. All hourly USD values are averaged into the month's average USD balance for that wallet.
- Apply the rate. 0.5% annualized on that average — divided by 12 for the month — is the monthly custody fee for that wallet.
- Bill per wallet. Each wallet is a separate line item; statements arrive by email on the payment date and live on your account page.
Worked example — $25,000 average BTC wallet
| Step | Calculation | Result |
|---|---|---|
| Annualized custody | 0.5% × $25,000 | $125.00 /yr |
| Monthly charge | $125 ÷ 12 | $10.42 |
| Displayed as | USD · AED · BTC (if wallet is your payment method) | 3 lines |
A wallet that moves around intra-month is treated with the same fairness: the fee keyfollows the average, with price spikes that occur inside a single hour normalized rather than penalized. Historical note for the careful reader: transactions in the final hour of the month roll into the next month's average — carry, not clip.
Autopay: how the bill gets collected
The custody fee is charged on the payment date of each billing month against your selected payment method — which can be one of your own wallets. If a wallet is your payment method, you authorize Changer.ae to move funds from it to cover the charge. Close a wallet early and its fees for that month settle at closure. Unpaid fee balances remain your obligation until settled.
Why structure beats rate-shopping
A custody fee buys reconciliation, segregation, and liability architecture — measure the product, not only the percentage. When an aggregator quotes "free custody," ask whose balance sheet your claim lives in. At Changer.ae: regulated, published,receipts on every line.
