Add logic to Account Numbers

In Mexico, a Fintoc Account Number uses the standardized Mexican bank account number (CLABE) format. You can assign an Account Number to a user’s payments or create a single-use Account Number for a payment order. Use this guide to disable an Account Number and set minimum and maximum amount limits. These controls let Fintoc reject unwanted inbound transfers.

Disable an Account Number

When you disable an Account Number, Fintoc rejects every inbound transfer to that Account Number and returns the transfer to the sender. Disable an Account Number when it should no longer receive payments.

Example use cases

Your company assigns one Account Number per user. When a user completes offboarding from your app, disable the user’s Account Number. Fintoc then returns payments sent to that Account Number.
Your company assigns one Account Number per order. After a customer pays, disable the order’s Account Number to avoid accepting a duplicate payment. If the customer pays twice, Fintoc returns the second payment.

Disable an Account Number with the API

curl --request PATCH \
     --url https://api.fintoc.com/v2/account_numbers/acno_test_a1b2c3d4e5f6 \
     --header 'Authorization: sk_test_jKaHdEa3mfmP0D105H' \
     --header 'accept: application/json' \
     --header 'content-type: application/json' \
     --data '
{
  "status": "disabled"
}
'

const accountNumber = await fintoc.v2.accountNumbers.update(
  "acno_test_a1b2c3d4e5f6",
  { status: "disabled" }
);

account_number = client.v2.account_numbers.update(
  "acno_test_a1b2c3d4e5f6",
  status="disabled"
)

The API returns the updated Account Number with its status set to disabled:

{
  "id": "acno_test_a1b2c3d4e5f6",
  "object": "account_number",
  "account_id": "acc_test_b2c3d4e5f6g7",
  "created_at": "2026-06-22T12:00:00.000Z",
  "deleted_at": null,
  "description": "My payins",
  "is_root": false,
  "last_transfer_at": null,
  "metadata": {},
  "mode": "test",
  "number": "000000000000000000",
  "options": null,
  "status": "disabled",
  "updated_at": "2026-06-22T12:00:00.000Z"
}

Set inbound transfer amount limits

You can restrict which inbound transfers an Account Number accepts. If a transfer does not meet your criteria, Fintoc rejects the transfer. Rejected transfers do not appear on your account statements or incur fees. Set min_amount and max_amount in the smallest currency unit. For example, 30000 represents 300.00 MXN. Fintoc supports three kinds of amount limits:

Limit	Description
Minimum amount	Set `min_amount` to reject any transfer with an amount lower than this value.
Maximum amount	Set `max_amount` to reject any transfer with an amount higher than this value.
Exact amount	Set both `min_amount` and `max_amount` to the same value to reject any transfer that does not match that specific amount.

Set limits with the API

curl --request POST \
     --url https://api.fintoc.com/v2/account_numbers \
     --header 'Authorization: sk_test_jKaHdEa3mfmP0D105H' \
     --header 'accept: application/json' \
     --header 'content-type: application/json' \
     --data '
{
  "account_id": "acc_test_b2c3d4e5f6g7",
  "options": {
    "min_amount": 30000,
    "max_amount": 40000
  }
}
'

const accountNumber = await fintoc.v2.accountNumbers.create({
  account_id: "acc_test_b2c3d4e5f6g7",
  options: {
    min_amount: 30000,
    max_amount: 40000,
  },
});

account_number = client.v2.account_numbers.create(
  account_id="acc_test_b2c3d4e5f6g7",
  options={
    "min_amount": 30000,
    "max_amount": 40000,
  },
)

The API returns the new Account Number with the amount limits under options:

{
  "id": "acno_test_a1b2c3d4e5f6",
  "object": "account_number",
  "account_id": "acc_test_b2c3d4e5f6g7",
  "created_at": "2026-06-22T12:00:00.000Z",
  "deleted_at": null,
  "description": "My payins",
  "is_root": false,
  "last_transfer_at": null,
  "metadata": {},
  "mode": "test",
  "number": "000000000000000000",
  "options": {
    "max_amount": 40000,
    "min_amount": 30000
  },
  "status": "enabled",
  "updated_at": "2026-06-22T12:00:00.000Z"
}

Test the integration

Confirm the disabled status and amount-limit behavior in test mode before going live. Use a test secret API key (sk_test_...) and a test Account Number. To test a disabled Account Number, disable the Account Number with the request above. Then simulate an inbound transfer to the disabled Account Number’s number. Fintoc rejects the transfer and returns it to the sender. The transfer does not appear on your account statement or incur a fee. To test amount limits, create an Account Number with min_amount set to 30000 and max_amount set to 40000. Then simulate two inbound transfers:

A transfer of 35000 (350.00 MXN) falls within the limits, so Fintoc accepts the transfer.
A transfer of 20000 (200.00 MXN) falls below min_amount, so Fintoc rejects the transfer and returns it to the sender.

Use the Simulate receiving a transfer endpoint to simulate inbound transfers in test mode.

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Add logic to Account Numbers

Disable an Account Number

Example use cases

Disable an Account Number with the API

Set inbound transfer amount limits

Set limits with the API

Test the integration

​Disable an Account Number

​Example use cases

​Disable an Account Number with the API

​Set inbound transfer amount limits

​Set limits with the API

​Test the integration

Disable an Account Number

Example use cases

Disable an Account Number with the API

Set inbound transfer amount limits

Set limits with the API

Test the integration