Sandbox configuration

Configure sandbox-only testing utilities to simulate flows that differ from production behavior.

Overview

Use the sandbox environment to test onboarding, KYC/KYB, pay-ins, webhooks, and transfer flows without triggering production money movement or production verification decisions.

Sandbox utilities are only available for testing. Do not use sandbox command URLs or simulation endpoints in production integrations.

Stub KYC applicant approval

In sandbox, you can stub a Sumsub applicant review and mark the applicant as approved.

You can approve the applicant in either of these ways:

Call the sandbox endpoint directly with the account ID whose KYC/KYB status you want to approve:

POST /dev/sumsub/applicants/{{accountId}}/approve

Replace {{accountId}} with the sandbox account ID.

Use the sandbox approval tool:

https://dev.sandbox.due.network/commands/sumsub/approve-applicant

Use this when you need to test flows that depend on a completed KYC/KYB status, such as:

creating gated virtual accounts after KYC/KYB approval;
testing endorsement flows;
testing post-KYC onboarding steps;
validating webhook handling for status changes.

This endpoint and tool are sandbox-only. In production, KYC/KYB status is determined by the normal verification review process.

Simulate pay-ins

In sandbox, you can simulate an incoming pay-in instead of sending funds from an external bank or wallet.

Use the sandbox pay-in simulation endpoint:

POST /dev/merge/v1/payin

The request can include the pay-in amount, currency, rail, reference, sender, and recipient details used for the test scenario.

Example shape:

{
  "currency": "EUR",
  "rail": "bank_sepa",
  "amount": "100.00",
  "reference": "test-reference",
  "sender": {
    "schema": "bank_sepa"
  },
  "recipient": {
    "schema": "bank_sepa"
  }
}

Use pay-in simulation to test:

virtual account deposit handling;
transfer status updates after funds are received;
webhook delivery for incoming payment flows;
reconciliation logic in your application.

The exact sender and recipient schema fields depend on the rail you are simulating. Use the same schema structure that applies to the relevant payment method.

Production differences

Sandbox commands and simulation endpoints replace external actions for testing only.

Flow	Sandbox behavior	Production behavior
KYC/KYB approval	You can stub applicant approval with `/dev/sumsub/applicants/{{accountId}}/approve` or the sandbox approval tool.	Approval is determined by the verification review process.
Pay-ins	You can simulate incoming funds with `/dev/v1/payin`.	Funds must arrive through the external bank, wallet, or payment rail.
Webhooks	Use simulated actions to trigger and validate webhook handling.	Webhooks are triggered by real production events.

Recommended testing flow

Create a sandbox account.
Start KYC/KYB for the account.
Call /dev/sumsub/applicants/{{accountId}}/approve or use the sandbox approval tool when you need the applicant to be approved.
Create the virtual account, transfer, or endorsement you want to test.
Call /dev/merge/v1/payin for flows that depend on incoming funds.
Verify webhook delivery and update your internal records from the webhook payloads.