# Multi-customer payment advice sync to WeClapp

Sync payment advice allocations to WeClapp when one bank inflow covers multiple customers.

Some **payment advices** allocate lines across **multiple WeClapp customers** (one bank inflow, several parties). Cortena syncs allocations per customer: the **UI session** switches the **bank transaction customer** context for each party, while **API token** integrations allocate without manual customer switching in the browser.

**Who this is for:** AR teams handling partner bulk payments (one transfer, many customer numbers) and admins configuring WeClapp credentials in Settings.

Related: [Payment advice: Sync to WeClapp](https://help.cortena.ai/guides/advanced/payment-advice-sync-weclapp) and [Payment advice workspace](https://help.cortena.ai/guides/advanced/payment-advice-workspace).

## 1. Multi-customer lines on one advice

Payment advice **Preview** shows lines grouped by customer when OCR or import found multiple parties:

- Each line maps to a receivable invoice number and customer.
- Totals per customer must align with the advice and bank amount before sync.

Unmatched lines stay in **needs review** until invoice numbers resolve. See [Payment advice workspace](https://help.cortena.ai/guides/advanced/payment-advice-workspace).

## 2. UI session: bank transaction customer

When you **Sync to weclapp** from the browser for a multi-customer advice:

1. Cortena processes allocations **per WeClapp customer**.
2. For each party, the session may switch which **customer** is attached to the **linked bank transaction** view (UI-only context), so WeClapp receives applications under the correct party.
3. Watch the workspace banner or step indicator when the active customer changes.

Operators should not change bank links mid-sync. Wait for completion or cancel a stuck job per [Payment advice: Sync to WeClapp](https://help.cortena.ai/guides/advanced/payment-advice-sync-weclapp).

## 3. API token path

With WeClapp connected via **Settings → Integrations → WeClapp** (API token):

- Background write-back can allocate all customers on the advice without manual UI switching.
- Ensure token scopes cover sales invoices and payment applications.

## Tips and limitations

- Never assume a single customer on the payment advice header. Always review line-level customers.
- HubSpot-imported advices may need **Search in CRM** hydration before all lines match. See [Payment advice CRM and HubSpot import](https://help.cortena.ai/guides/advanced/payment-advice-crm-hubspot).
- Related: [Open items and payment write-back staging](https://help.cortena.ai/guides/advanced/open-items-write-back).

## Quick reference

| Task | Where |
| --- | --- |
| Review parties | Payment advice → **Preview** lines |
| UI sync | **Sync to weclapp** (customer context may switch) |
| Credentials | **Settings → Integrations → WeClapp** |
| Stuck sync | **Retry** / **Cancel** ([WeClapp sync](https://help.cortena.ai/guides/advanced/payment-advice-sync-weclapp)) |