DOCS/FLUX/Wht Filing

Batch Filing

Submit multiple Withholding Tax (WHT) transactions in one request for processing and filing via the FLUX API. This endpoint is ideal for bulk vendor payments or periodic WHT remittance.

Use this when:

You are filing WHT for multiple vendors or payments
You are processing payroll, contracts, or bulk disbursements
You want efficient, consolidated tax filing

HTTP Request

POSThttps://api.taxstreem.com/v1/flux/wht-filing/batch

Request Body

The following parameters are required for this action.

Parameter	Type	Description
batchId	string	Unique identifier for the batch.
payload	array	List of single filing objects (encryptedPayload,month,year, beneficiaryName, beneficiaryTin, transactionDate, transactionDesc, transactionAmount, rate, taxAmount, scheduleReference).

Encrypted Payload (In-Flight Encryption)

FLUX requires sensitive credentials to be encrypted at the application layer before transmission. This provides defense-in-depth on top of HTTPS.

The encryptedPayload field must contain a Base64-encoded AES-256-GCM encrypted JSON object.

Encryption Specification

Property	Value
Algorithm	AES-256-GCM
Key Derivation	SHA-256(sharedSecret)
IV (Nonce)	12 bytes (96-bit) random
Auth Tag	16 bytes (128-bit)
Encoding	Base64

Payload Format

The final transmitted value must be:

Base64( IV[12] || Ciphertext || AuthTag[16] )

IV is randomly generated per request
Ciphertext is encrypted JSON
AuthTag is automatically appended by GCM

Example Request

curl -X POST https://api.taxstreem.com/v1/flux/wht-filing/batch \
  -H "x-api-key: txsm_test_SK489c..." \
  -H "Content-Type: application/json" \
  -d {
    "batchId": "batch_123",
    "payload": [
      {
        "encryptedPayload": 'encrypted_string_...',
        "filingId": '123-abuiod-90',
        "month": 1,
        "year": 2024,
        "data": [
           {
               "beneficiaryName": "John Doe",
               "beneficiaryTin": "2345544-0001",
               "transactionDate": "2024-03-20",
               "transactionDesc": "Consultancy Services",
               "transactionAmount": 50000,
               "rate": 5,
               "taxAmount": 2500,
               "scheduleReference": "REF-123456"
           }
        ]
      }
          ]
     }

Example Response

202 Accepted

{
  "status":  "accepted",
  "message":  "schedule accepted successfully",
  "data":  {
    "id":  "xaee2ddf-effvkfes",
    "created_at":  "2026-02-20T10:00:00Z"
  }
}