# Connect to the ASP (Taxilla): test, UAT and live modes

> Choose how invoices are submitted, enter your Taxilla credentials, test the connection and understand the three modes.

Source: /help/en/settings/e-invoicing-connection

Alya Books reports tax invoices to the FTA through an accredited service provider, Taxilla. The connection has three modes, so you can practise safely before real submissions.

## The modes

| Mode | What happens |
|---|---|
| Test (simulated) | Nothing leaves the app. Submissions follow a scenario you pick and are marked TEST. |
| Taxilla UAT | Taxilla's test environment (`uat.entransact.taxilla.com`). Needs the UAT client ID and secret from Taxilla. |
| Taxilla Live | Real submissions to the UAE Peppol network and the FTA. Use only after UAT passes. |

## Steps

1. Go to **Settings → E-invoicing**. Owners and admins can change it.
2. Under **Connection mode**, pick a mode.
3. For Test, choose a **Test scenario**: Always accept, Slow processing, Rejected by Taxilla, Rejected by buyer, or Rejected by FTA. It applies to new submissions.
4. For UAT or Live, fill in **Taxilla credentials**: **Client ID** and **Client Secret**, as issued by Taxilla during your onboarding with them. **Base URL** stays empty: each mode has its host (`https://uat.entransact.taxilla.com/accesspoint/v1`, `https://live.entransact.taxilla.com/accesspoint/v1`), and you only fill it in if Taxilla names another one. Leave a field blank later to keep the saved value. Your **Peppol ID** under **Settings → Company profile** must be the one Taxilla issued with these credentials.
5. Click **Save connection**, then **Test connection**. The **Connection status** card shows the active mode, the last test result and time.

## Good to know

- **Validation strictness** on the same tab has a switch **Treat warnings as errors**. With it on, an invoice with a warning cannot be issued until the warning is fixed. Notes that only explain what Alya Books sends, such as a buyer without a TRN, stay warnings. Errors always block, with or without the switch.
- Under **Settings → Company profile**, **Legal registration type** says what the number in **Trade License Number** is: a trade licence (with its licensing authority), an Emirates ID, a passport (with its two-letter issuing country) or a cabinet decision.

- Credentials are stored on the server only and never sent back to the browser. **Remove saved credentials** clears them. **Test connection** asks Taxilla for an access token and shows how long it is valid.
- Live mode sends real tax documents. Issued documents cannot be deleted or reset, only corrected with credit or debit notes.
- You can switch back to Test at any time; documents already sent keep their UAT or Live status.
- Submissions in UAT and Live use submission credits from your plan.
- Timeline: pilot from 1 July 2026; businesses with revenue of AED 50 million or more must appoint an ASP by 30 October 2026 and go live on 1 January 2027; all other businesses on 1 July 2027; government entities on 1 October 2027.
- In Test mode, **Incoming Invoices → Simulate received invoice** delivers generated supplier invoices for the scenario you choose (valid ones and ones that fail validation), so you can try receiving, review and payment without Taxilla. See [Simulate received invoices](/help/en/incoming-invoices/simulate-received-invoices).

## Related

- [Company data and TRN](/help/en/account-and-setup/company-data-and-trn)
- [Plans, credits and fee invoices](/help/en/account-and-setup/plans-and-credits)
- [Peppol IDs for your contacts](/help/en/contacts/peppol-id-lookup)