Mercury · Rate Limits

Mercury Rate Limits

Mercury does not publish a numeric per-second rate-limit ceiling for the public API. Excessive calls return HTTP 429 Too Many Requests. The Plus tier caps invoicing API invoice-creation at 500 per month; Pro removes that ceiling. Read-and-write tokens must be issued from a whitelisted set of source IPs - calls from other IPs return 401/403 rather than 429.

4 Limits Throttle: 429
BankingFintechStartupsTreasuryPaymentsRate LimitingThrottling

Limits

Per-Token Throttle token
requests · minute
dynamic
Mercury throttles per-token request rate; numeric ceiling not published. 429 is returned when the threshold is exceeded.
Plus - Invoicing API Quota account
invoice_created · month
500
Plus tier; invoice creation via API capped at 500 per calendar month.
Pro - Invoicing API Quota account
invoice_created · month
-1
Pro tier; unlimited invoice creation via API.
IP Allowlist (Read-Write Tokens) token
source_ip
allowlisted
Read-and-write tokens may only be used from the IP addresses listed when the token was issued; other IPs receive 401/403.

Policies

429 Throttling
When per-token thresholds are exceeded the API returns 429 Too Many Requests.
Backoff Strategy
Implement exponential backoff with jitter on 429 and 5xx responses. Cache idempotent reads (account list, statements) to reduce volume.
IP Allowlisting
Read-write tokens are bound to a fixed set of source IPs. Rotate the allowlist via Settings before deploying calls from new infrastructure.

Sources