Shipping breaks at 2am.
We answer by morning.

API keys are shown once at creation and cannot be retrieved afterward — this is a security measure. Go to your Dashboard, revoke the lost key, and generate a new one. Your usage history and billing are tied to your merchant account, not individual keys, so nothing is lost.

Sign into the Dashboard with your current key. Under the API Keys section, click "Revoke" on the old key. Then generate a new key. Best practice: update your application with the new key before revoking the old one to avoid downtime.

Common causes:
1. Missing header — requests must include X-API-Key: rv_live_your_key.
2. Wrong prefix — production keys start with rv_live_, sandbox with rv_test_.
3. Revoked key — check your Dashboard for key status.
4. Whitespace — ensure no trailing spaces or newlines in the header value.
See the Authentication docs for full details.

A 403 means your plan doesn't include that endpoint. For example, label creation requires the Growth plan or higher, and BYOK requires Pro. Check the endpoint summary for plan requirements. Upgrade from your Dashboard — changes take effect immediately.

Rate limits depend on your plan:
Sandbox (free): 30 req/10 sec (IP-limited)
Starter ($29/mo): 120 req/min, 5,000 req/month
Growth ($79/mo): 300 req/min, 25,000 req/month
Pro ($199/mo): 600 req/min, 100,000 req/month
Enterprise ($499/mo): Custom limits
Check response headers X-RateLimit-Remaining on every request. See Rate Limit docs.

A 429 means you've exceeded your rate limit. No data is lost and no extra charges apply — the request is simply rejected. The response includes a retry_after field (in seconds). Wait that long, then retry. If you're consistently hitting limits, upgrade your plan for higher throughput.

Go to your Dashboard and click "Manage Billing." This opens the Stripe billing portal where you can upgrade, downgrade, update your card, or change your billing email. Plan changes take effect immediately — you're prorated for the remainder of the billing cycle.

Open the billing portal from your Dashboard (Quick Actions > Manage Billing). Click "Cancel plan." Your API key stays active until the end of the current billing period — you won't lose access mid-month. No cancellation fees, no contracts.

We don't offer refunds for partially used billing periods, but you can cancel at any time and your access continues until the period ends. If you were charged in error or have an exceptional circumstance, use the contact form below and we'll resolve it.

BYOK is available on Pro and Enterprise plans. Steps:
1. Get credentials from the USPS Developer Portal (client ID, client secret, CRID, MID).
2. Store them via POST /api/byok/credentials.
3. Verify with POST /api/byok/verify.
Your credentials are AES-GCM encrypted at rest. See the BYOK docs for the full API reference.

Run GET /api/byok/status to check credential health. Common issues:
1. Expired USPS token — we auto-refresh, but if your client secret changed on the USPS portal, re-submit credentials.
2. Wrong CRID/MID — these must match your USPS Developer Portal registration exactly.
3. Plan mismatch — BYOK requires Pro ($199/mo) or Enterprise.
If status shows "verified" but requests fail, the issue is likely on the USPS side. Check OAuth troubleshooting.

Sandbox (rv_test_ keys): Free, 30 req/10 sec, hits the live USPS API (real validation results), no label creation. Perfect for development and testing.
Production (rv_live_ keys): Paid plans, higher rate limits, full feature access including labels and BYOK.
Get a free sandbox key — no credit card required. Upgrade when you're ready to ship.

The fastest way — validate an address with curl:

Address validation works without a key (free tier). For authenticated endpoints, add -H "X-API-Key: rv_test_your_key". Or use our live API playground. SDKs available for Python and Node.js.

Three endpoints work without authentication, IP-rate-limited at 30 req/10 sec:
1. GET /api/address/validate — Address validation
2. GET /api/address/city-state — City/state lookup by ZIP
3. POST /api/rates — Domestic rate shopping
Everything else requires an API key. See the full endpoint table.