DOCS/flux/vat-filing

Batch VAT Filing

Authentication Required

This endpoint requires a valid API key in the x-api-key header of every request.

The Batch VAT Filing API processes multiple Value Added Tax transactions in a single request. Ideal for end-of-day reconciliation flows, bulk invoice uploads, or ERP integrations where many line items accumulate before submission.

Integration Flow

1Encrypt Credentials: Generate your encryptedPayload once per request — it covers all items in the batch.
2Assemble the Batch: Collect all VAT line items into the data array.
3Handle Result: Listen for vat.filing.success webhooks — one event is emitted per batch.

HTTP Request

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

Request Body

Top-level parameters for the batch request.

Parameter	Type	Required	Description
batchId	string	Required	Unique idempotency key for this batch request. Prevents duplicate batch submissions.
payload	array	Required	Array of filing item objects to be processed in batch (see schema below).

payload[ ] — Batch Filing Item Schema

Field	Type	Required	Description
encryptedPayload	string	Required	AES-256-GCM encrypted TaxPromax credentials. See Encryption Guide.
filingId	string	Required	Unique filing identifier / idempotency key for this item.
month	number	Required	Numeric month being filed (`1`–`12`).
year	number	Required	4-digit filing year (e.g. `2026`).
vatAmount	number	Required	Total VAT amount to file.
taxId	string	Required	Tax Identification Number (TIN) for the business entity.
interestAmount	number	Required	Accrued interest amount if filing past statutory deadline.
penaltyAmount	number	Required	Late filing penalty amount if applicable.
scheduleUrl	string	One of	URL of a schedule workbook you built yourself (xlsx). Use this instead of `sales` / `purchases` for large entries. Send inline rows or `scheduleUrl`, not both.
sales	array	One of	Inline sales for the VAT return (max 500 rows) — we place them on the NRS "A - Sales" schedule. See the `sales[]` item below.
purchases	array	One of	Inline purchases for the VAT return (max 500 rows) — we place them on the NRS C_2 purchases list. See the `purchases[]` item below.

Send the schedule in one of two ways. Either inline: sales and/or purchases (up to 500 rows each), from which we build the NRS VAT schedule workbook for you. Or as a workbook you built yourself, via scheduleUrl, which is the route for large entries. Sending inline rows together with scheduleUrl, or neither, returns 400 Bad Request. Send only purchases for a nil-sales return. When you send inline rows we build and upload the workbook before accepting the request, so the response can take around 20 seconds. A batch may carry inline rows for at most 10 filings; use scheduleUrl for the rest.

sales[] item

Parameter	Type	Required	Description
customerName	string	Required	Name of the customer.
customerTaxId	string	Optional	Customer Tax ID. If omitted it is filed as `0`.
item	string	Required	Product or service name.
description	string	Optional	Product or service description.
vatStatus	string	Required	VAT treatment: `standard-rated`, `zero-rated` or `vat-exempt`.
state	string	Optional	Place of consumption: a Nigerian state name, ISO code (e.g. `NG-LA`) or `FCT`. Defaults to Lagos. An unknown state returns 400.
lga	string	Optional	Place of consumption: Local Government Area. Left blank if omitted.
amountExclVat	number	Required	Sale amount excluding VAT, filed exactly as given. Must be 0 or more.

purchases[] item

Parameter	Type	Required	Description
sellerName	string	Required	Name of the supplier.
sellerTaxId	string	Optional	Supplier Tax ID. If omitted it is filed as `0`.
description	string	Required	What was purchased.
amountExclVat	number	Required	Purchase amount excluding VAT. Must be 0 or more.
vatStatus	string	Required	VAT treatment: `standard-rated`, `zero-rated` or `vat-exempt`.
supplyType	string	Required	`goods` or `service`. Purchases without a supply type cannot be placed on the schedule.

Encrypted Payload

FLUX requires sensitive credentials to be encrypted at the application layer. One encryptedPayload covers the entire batch.

The encryptedPayload must be a Base64-encoded AES-256-GCM encrypted JSON object containing your TaxPromax email and password.

Idempotency

The batchId you send is the idempotency key for this request. It lets you retry safely after a timeout or network error without filing, or being charged, twice. Keys are tracked per environment, so a sandbox request never collides with a production one.

You send	You get
A new `batchId`	The batch is accepted and charged as normal.
The same `batchId` with the same payload	The original response again, with `"replayed": true`. Nothing is filed or charged a second time.
The same `batchId` with a different payload	`409 Conflict`. Use a new `batchId` for a different batch.
The same `batchId` while the first request is still processing	`409 Conflict`. Wait a moment and retry; you will then receive the replayed response.
The same `batchId` after a failed request (400, 402, 403, 5xx)	Treated as a fresh request. A failed request releases the key, so you can fix the problem and retry with the same `batchId`.

A replayed response looks like this:

{
  "status": "accepted",
  "message": "batch filing accepted successfully",
  "data": { ... same as the original response ... },
  "replayed": true
}

The payload comparison ignores encryptedPayload, so re-encrypting the same filing for a retry is still a replay. Replays are remembered for 7 days.

Response

Returns 202 Accepted on success. Filing is processed asynchronously — listen for the vat.filing.success webhook for the final outcome.

HTTP Status	Error Key	Cause & Resolution
400	Bad Request	Missing or invalid fields. Check the `errors` array for field-level detail.
401	Unauthorized	Missing or invalid `x-api-key` header.
402	Payment Required	Your credit balance is too low for this request. Each filing costs 2 credits, and a balance of 4 or fewer is treated as empty. Top up your credits, then retry with the same `batchId`.
403	Forbidden	No active subscription for this service, or the API key belongs to a plan that does not include Flux. Sandbox keys (`txsm_test_`) are not affected. Subscribe to Flux, or use a key from a Flux plan.
409	Conflict	The `batchId` was already used with a different payload, or the first request with this `batchId` is still being processed. Use a new `batchId` for a different filing. If the first request is still processing, wait briefly and retry with the same payload to receive the replayed response.
429	Too Many Requests	Rate limit exceeded. Backoff using the `Retry-After` header.

Example Request

curl -X POST https://api.taxstreem.com/v1/flux/vat-filing/batch \
  -H "x-api-key: txsm_test_SK489c..." \
  -H "Content-Type: application/json" \
  -d '{
   "batchId": "batch_2343dfw",
   "payload": [
      {
         "encryptedPayload": "aXZJVkpTT05...YWx1ZQ==",
         "filingId": "filing_2343dfw",
         "month": 1,
         "year": 2026,
         "vatAmount": 0,
         "taxId": "",
         "interestAmount": 0,
         "penaltyAmount": 0,
         "sales": [
            {
               "customerName": "Shoprite Nigeria Ltd",
               "customerTaxId": "1234567890123",
               "item": "Consulting retainer",
               "description": "March retainer",
               "vatStatus": "standard-rated",
               "state": "Lagos",
               "lga": "Ikeja",
               "amountExclVat": 900000
            }
         ],
         "purchases": [
            {
               "sellerName": "Acme Consulting Ltd",
               "sellerTaxId": "1234567890123",
               "description": "Consulting, March",
               "amountExclVat": 250000,
               "vatStatus": "standard-rated",
               "supplyType": "service"
            }
         ]
      }
   ]
}'

Example Response

202 Accepted

{
  "status":  "accepted",
  "message":  "schedule accepted successfully",
  "data":  {
    "id":  "xaee2ddf-batch-90",
    "created_at":  "2026-02-20T10:00:00Z"
  }
}