By default, Request applies real-time rates during payment (→ Which conversion rates does Request Finance use?). If you prefer to fix rates between fiat (e.g. USD) and stablecoins (e.g. USDC), you can navigate to Settings > Product Settings and activate "1:1 Stablecoin Conversion".
What happens when the conversion rate is fixed?
When you fix the conversion rate, fiat-denominated payables and receivables in supported stablecoins will automatically use a 1:1 rate, provided they’re created by you or your team members.
Affected payables & receivables
This settings affects any payable and receivable that is created by you, such as:
Invoices you sent to clients
Salaries for your employees
Direct Payments to your contacts
Bills you import
Expenses sent to you by your employees
Notably, it does not apply to:
Invoices sent to you by vendors through Request Finance
Supported stablecoins
When enabling the 1:1 fixed rates, it'll be applied to the following stablecoins and fiat currencies:
US Dollar (USD) stablecoins
USDC*
USDT*
DAI*
REUSD
USDS
FRXUSD
*And variants (e.g. bridged versions).
Euro (EUR) stablecoins
EURC*
EURe
cEUR
agEUR
EUROe
Mexican Peso (MXN) stablecoins
MXNB
*And variants (e.g. bridged versions).

