Bulk Charge

In A Nutshell
In a nutshell

Build a recurring system for accepting payment from multiple customers.

After accepting the first payment for goods and services from your customer, you can save the authorization of the payment for returning customers. Authorizations allow you to build a custom recurring payment system with minimal intervention from the customer. As your customer base grows, so does the complexity of building a recurring payment system.

The Bulk ChargeAPI endpoints abstract these complexities, providing you with a simple interface to interact with.

How it works

When you have multiple customers to charge at regular intervals, it’s recommended that you send a group of charges per request as opposed to initiating a request per charge. This is to avoid rate limiting, while ensuring you have a scalable system as your business grows.

The Bulk ChargeAPI endpoint works with batches (batch processing) and charge objects. A batch consists of a collection of charge objects with the following parameters:

amountYesIntegerThe amount to charge the customer.
authorizationYesStringThe authorization code from a previously completed transaction.
referenceNoStringA unique identifier for the charge.
attempt_partial_debitNoBooleanA flag to indicate if you want us to try recouping lower amounts when the customer has insufficient funds.
at_leastNoIntegerThis is used in addition with the attempt_partial_debit parameter. It’s used to set the amount we should retry if the actual amount fails.
metadataNoObjectThis is to hold custom data for post-payment processes.

The charges in a batch are queued when received and processed at intervals. During processing, if a charge fails, we add the charge back to the queue for further retry.

The table below shows the metric you need to keep in mind when planning your batch:

Max batch size1000The total number of charges that can be accepted per request.
Retry limit5The number of times we try processing a charge before we mark as failed.

Integration checklist

The number of charges in a batch is dependent on your use case and scale, so when planning your batch, here’s a checklist to reference:

  • Ensure your batch size is within the batch limit.
  • Always pass a reference to track each charge easily. References help with idempotency such that if you need to retry a particular charge again, you do not risk the chance of double debiting. In addition, you cannot use the same authorization in a batch without a reference. If you need to charge an authorization multiple times in a batch, pass a reference for each charge.
  • Pass the attempt_partial_debit parameter if your business has a high rate of payment default.
  • When building your retry logic, try checking the gateway_response in the data object. The gateway response tells you if it’s a customer error or processing error. For customer errors, you need to reach out to them to resolve the issue, while for processing error, you can retry using the same reference.

Create a bulk charge

With your batch and charge design is in place, you can make a POST request to the Initiate Bulk ChargeAPI endpoint, passing each charge object to the batch:

Show Response
3authorization="Authorization: Bearer YOUR_SECRET_KEY"
4content_type="Content-Type: application/json"
6 {
7 "amount": 10000,
8 "authorization": "AUTH_ncx8hews93",
9 "reference": "my_reference_1"
10 },
11 {
12 "amount": 15000,
13 "authorization": "AUTH_200nvt70zo",
14 "reference": "my_reference_2"
15 },
16 {
17 "amount": 25000,
18 "authorization": "AUTH_84bqxd3rkf",
19 "reference": "my_reference_3"
20 }
23curl "$url" -H "$authorization" -H "$content_type" -d "$data" -X POST
2 "status": true,
3 "message": "Charges have been queued",
4 "data": {
5 "batch_code": "BCH_ml3zk2hregr1inj",
6 "reference": "bulkcharge-1713528671888-29smeabva5",
7 "id": 191016934,
8 "integration": 463433,
9 "domain": "test",
10 "status": "active",
11 "total_charges": 3,
12 "pending_charges": 3,
13 "createdAt": "2024-04-19T12:11:11.000Z",
14 "updatedAt": "2024-04-19T12:11:11.000Z"
15 }

The batch_code in the data object of the response allows you track and manage the batch, hence, it’s recommended that you save it for later use. There are two other parameters that gives you more details about the batch:

  1. total_charges: This is the total number of charge objects available in the batch.
  2. pending_charges: This is the amount of charges left to be processed.

Listen to notifications

As previously mentioned, charges are queued before being processed, so you need to implement a webhook URL to get the status of each charge in a batch. While you might have sent multiple charges per batch, we send a webhook event for each charge in the batch. For example, if your batch contains 100 charges and all were successfully processed, you would get 100 events.

2 "event": "charge.success",
3 "data": {
4 "id": 3725529423,
5 "domain": "test",
6 "status": "success",
7 "reference": "my_reference_3",
8 "amount": 25126,
9 "message": null,
10 "gateway_response": "Approved",
11 "paid_at": "2024-04-19T12:12:15.000Z",
12 "created_at": "2024-04-19T12:12:12.000Z",
13 "channel": "card",
14 "currency": "NGN",
15 "ip_address": null,
16 "metadata": {
17 "custom_fields": [
18 {
19 "display_name": "Bulkcharge ID",
20 "variable_name": "bulkcharge_id",
21 "value": "191016934"
22 },
23 {
24 "display_name": "Bulkcharge batch code",
25 "variable_name": "bulkcharge_batch_code",
26 "value": "BCH_ml3zk2hregr1inj"
27 },
28 {
29 "display_name": "Charged via",
30 "variable_name": "charged_via",
31 "value": "Bulkcharge"
32 }
33 ]
34 },
35 "fees_breakdown": null,
36 "log": null,
37 "fees": 126,
38 "fees_split": null,
39 "authorization": {
40 "authorization_code": "AUTH_84bqxd3rkf",
41 "bin": "408408",
42 "last4": "4081",
43 "exp_month": "12",
44 "exp_year": "2030",
45 "channel": "card",
46 "card_type": "visa ",
47 "bank": "TEST BANK",
48 "country_code": "NG",
49 "brand": "visa",
50 "reusable": true,
51 "signature": "SIG_yEXu7dLBeqG0kU7g95Ke",
52 "account_name": null,
53 "receiver_bank_account_number": null,
54 "receiver_bank": null
55 },
56 "customer": {
57 "id": 112907911,
58 "first_name": "Mizz",
59 "last_name": "Kaneah",
60 "email": "[email protected]",
61 "customer_code": "CUS_lht026y5q7p27o5",
62 "phone": "245421361",
63 "metadata": {},
64 "risk_action": "default",
65 "international_format_phone": "+245421361"
66 },
67 "plan": {},
68 "subaccount": {},
69 "split": {},
70 "order_id": null,
71 "paidAt": "2024-04-19T12:12:15.000Z",
72 "requested_amount": 25000,
73 "pos_transaction_data": null,
74 "source": {
75 "type": "api",
76 "source": "merchant_api",
77 "entry_point": "charge",
78 "identifier": null
79 }
80 }

At the moment, we only send webhook events for a successful charge. However, for various reasons, there might be issues processing the charge, so we recommend calling the Verify TransactionAPI endpoint for charges that you didn’t get an event for.