eSIM API Guide 2026: Integrate, Provision, Resell

What is an eSIM API?

An eSIM API is a REST interface between your application and a connectivity provider's provisioning system. Instead of shipping physical SIM cards or manually activating profiles, your backend sends an HTTP request and receives a digital profile (typically as a QR code) that your customer installs on their phone.

For resellers, the API replaces the need to negotiate wholesale agreements with dozens of carriers. You buy packages at wholesale rates, set your retail price, and the API handles activation across 210+ countries. OmaxTelecom's eSIM reseller API - Bappy - uses package-based billing: fixed GB bundles per destination, ideal for travel use cases.

The activation flow

A minimal eSIM API integration has four steps:

1. List packages - fetch available plans for a destination (country code, GB, validity).
2. Activate - POST with package ID and quantity. Response includes ICCID, status, and QR code (LPA string).
3. Deliver - show the QR code to your customer (on-screen, email, or PDF).
4. Confirm - listen for webhook events when the SIM activates on-network.

curl -X POST https://api.omaxtelecom.com/bapi/api/v1/esim/activate \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"package_id": "eu-3gb-15d", "quantity": 1}'

Authentication

Bappy uses Bearer token authentication. Open a developer account in the OmaxTelecom Console, top up your wallet (from €10) to get production keys straight away (KYC within 14 days), and pass them in the Authorization header. Keys are organization-scoped with full data isolation. For OIDC-based auth (OAuth 2.0 Client Credentials), see Telkor - OmaxTelecom's per-MB connectivity platform for IoT and MVNO use cases.

Webhooks and events

Production eSIM integrations should not poll for status. Configure webhook endpoints to receive real-time events:

• sim.activated - profile installed and connected on-network
• sim.expired - validity period ended
• sim.usage_threshold - data consumption hit a configured limit
• sms.delivered - SMS sent via the SIM profile
• bulk.completed - batch activation finished

Validate webhook signatures, respond with 2xx quickly, and process asynchronously. Full event catalogue: developer.omaxtelecom.com.

Testing in production

Bappy has no separate sandbox: you integrate directly against production. Start with a small wallet top-up (from €10) and test activation, QR delivery, webhook handling and error cases with a few low-cost packages before you open sales to customers. Production keys are available as soon as your account is open and topped up; business verification (KYC) must be completed within 14 days of sign-up.

Build vs buy

Building eSIM infrastructure from scratch means negotiating SM-DP+ agreements, carrier roaming contracts, GSMA compliance, and ongoing profile management. Realistic timeline: 12–24 months and significant CAPEX. Only carriers and licensed MVNOs should consider this path.

For travel apps, OTAs, agencies, and resellers, an eSIM reseller API is the right choice. You get tier-1 backbone coverage (BICS), 761 ready-made packages and a prepaid wallet from €10. Start with our eSIM API overview, then see Bappy.

Frequently asked questions