How to Integrate the PRA API with Your POS Software

Step 1 — Store your PRA credentials

PRA issues its own credential set. In TaxBridge you enter it once on the Authorities / Credentials form, which renders exactly the fields PRA needs:

Your own numeric POS ID (required in both sandbox and production) plus a production Bearer token. The sandbox Bearer token is a shared public value TaxBridge already holds.

Credentials are AES-256-GCM encrypted at rest and never returned to your app. Don't have production credentials yet? Turn on Use simulator (sandbox) and build your whole integration first — see how to test tax APIs.

Step 2 — Create an API key

Generate a key scoped to the test environment (and optionally pinned to PRA). The full key — tbk_test_... — is shown once and stored only as a SHA-256 hash. Keep it as a secret; a lost key is regenerated, not recovered.

Step 3 — POST your first PRA invoice

Send your canonical invoice to POST /api/v1/invoices with the PRA header and an Idempotency-Key:

curl -X POST https://taxbridge.themetasum.com/api/v1/invoices \
  -H "Authorization: Bearer tbk_test_9f3a21c7b4d6e8f0_..." \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: 0b6d1c4e-7f9a-4a51-8d3c-2e5f7a91b204" \
  -H "X-Tax-Authority: PRA" \
  -d '{
    "invoiceNumber": "INV-10001",
    "invoiceDate": "2026-08-10T10:30:00",
    "invoiceType": "Sale",
    "currency": "PKR",
    "paymentMode": "Cash",
    "customer": { "name": "Walk-in Customer" },
    "items": [{
      "description": "Chicken Karahi Full", "hsCode": "11001010",
      "quantity": 1, "unitPrice": 1500.00,
      "taxRate": 16, "taxAmount": 240.00, "total": 1740.00
    }],
    "subTotal": 1500.00, "tax": 240.00, "total": 1740.00
  }'

Print the returned qrCode on the receipt and store the submissionId so you can query status later.

The PRA quirk TaxBridge handles for you

PRA has no shared sandbox POS ID — you generate your own on the PRA portal. A non-numeric POS ID is reported as a configuration error naming the exact field. Buyer PNTN is carried on the payload.

Step 4 — Go to production

Once your sandbox flow is verified, complete company and branch configuration, store your production credentials and generate a tbk_live_ key. Sandbox and production stay completely separate — a sandbox key never files a real PRA invoice. See production onboarding.

Frequently asked questions