# Group Payment Integration (/docs/guides/integration/group-payment-integration) 

**Pre-requisites**

* [Setup your Hands In account](/docs/guides/getting-started/setup-your-account)  - You must have created and set up a Hands In account before following this tutorial
* [API Authentication](/docs/guides/authentication/authentication-overview) - You must have retrieved your sandbox or live API key

**How it works?**

<img src="/docs-assets/4ad93688e067d76ba8a5b9d7fbd86b9312c0d4f4c0a3b2e059e5de83dd54fad4-diagram-export-19-12-2024-03_23_03.svg" />

**Server-to-server integration steps**

1. **Create a group payment session** — `POST /v1/group-payments` with the total, the `lineItemParams`, a `splitType`, the group owner in
   `customer`, a unique `idempotencyKey` and (recommended in production) an `expirationDate`. See
   [Create a Group Payment Session](/docs/guides/group-payment/group-payment-sessions/create-a-group-payment-session) for full request and response
   examples.
2. **Redirect the group owner to `customerUrl`** — not `url`. The `url` field is the invite link that the owner shares with the rest of the group.
3. **Optionally invite members and pre-allocate items up front** — pass the `invites` and `itemAllocation` fields on creation so each member arrives
   at checkout with their share already assigned. See
   [How to pre-allocate items](/docs/guides/integration/psp-integration#how-to-pre-allocate-items).
4. **Receive the outcome** — subscribe to the group payment
   [webhook events](/docs/guides/group-payment/group-payment-webhooks), or poll
   [Retrieve a Group Payment Session](/docs/guides/group-payment/group-payment-sessions/retrieve-a-group-payment-session).
5. **Reconcile each member's contribution** — see
   [Reconcile Group Payments](/docs/guides/group-payment/group-payment-reconcilation).