Base Fiat Currency
Pronunciation: BAYS FEE-at KUR-un-see
Also known as: Account Base Currency, Merchant Base Fiat Currency, Reporting Base Currency
Definition
Base fiat currency is the primary government-issued currency a business uses to price, report, compare, or account for crypto payments. It provides a common reference for orders, exchange rates, revenue, and reconciliation even when the payer uses cryptocurrency. The base fiat currency is not necessarily the currency displayed to the customer, the currency quoted for one invoice, or the asset received in settlement.
Overview
Meaning and scope
Base fiat currency is the primary government-issued currency a business uses to price, report, compare, or account for crypto payments. It provides a common reference for orders, exchange rates, revenue, and reconciliation even when the payer uses cryptocurrency. The base fiat currency is not necessarily the currency displayed to the customer, the currency quoted for one invoice, or the asset received in settlement.
Mechanism and operation
Base Fiat Currency gives a merchant one consistent unit for financial reporting and operational comparison. A business may price products and maintain accounting in USD, EUR, or another fiat currency while accepting several cryptocurrencies through the same payment system. Those values can match the base currency, but they serve different purposes. When an invoice is created, the requested amount can be denominated in a supported fiat currency and converted into a Pay Currency. The system should record the original fiat amount, rate source, quote timestamp, and resulting crypto amount for later reconciliation. Changing the base currency affects reports, thresholds, and comparisons but should not rewrite historical transaction values.
Practical payment example
A storefront prices goods in euros but accepts cryptocurrency. Finance preserves the EUR invoice amount, exchange-rate snapshot and actual received asset units so price and settlement reports remain reconcilable.
Operational checks
Existing payments need their original pricing currency and rate evidence. Accounting systems may additionally translate transactions under formal reporting rules. Merchants operating across countries should avoid using one base currency as a substitute for local pricing or tax requirements. The base currency is an internal anchor, while customer presentation, settlement assets, and statutory reporting can use different units.
Distinctions and limits
It differs from Display Currency, which controls how prices appear to the payer, and from Quote Currency, which identifies the unit used for a particular exchange-rate quote.
Related reading
Related definitions: Display Currency, Quote Currency.
Example
A storefront prices goods in euros but accepts cryptocurrency. Finance preserves the EUR invoice amount, exchange-rate snapshot and actual received asset units so price and settlement reports remain reconcilable.
Comparison
It differs from Display Currency, which controls how prices appear to the payer, and from Quote Currency, which identifies the unit used for a particular exchange-rate quote. Those values can match the base currency, but they serve different purposes.
Key Takeaway
Base fiat currency is the merchant's primary reporting and pricing reference, not necessarily the currency displayed, quoted, paid, or settled.
Sources
- OxaPay API Reference: Generate Invoice — OxaPay (2026-08-02)
- OxaPay API Reference: Generate White Label — OxaPay (2026-08-02)
- OxaPay API Reference: Supported Currencies — OxaPay (2026-08-02)