Apply a single payment to multiple invoices (atomic create)

curl --request POST \
  --url https://api.arcuserp.com/v1/payments/multi-invoice-apply \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "account_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "amount": 5000,
  "auto_apply": true,
  "route_unapplied": "credit",
  "applications": [
    {
      "order_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "amount_applied": 2500
    }
  ],
  "check_number": "<string>",
  "check_date": "2023-12-25",
  "external_reference": "<string>",
  "notes": "<string>",
  "payment_date": "2023-12-25"
}
'

import requests

url = "https://api.arcuserp.com/v1/payments/multi-invoice-apply"

payload = {
    "account_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "amount": 5000,
    "auto_apply": True,
    "route_unapplied": "credit",
    "applications": [
        {
            "order_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
            "amount_applied": 2500
        }
    ],
    "check_number": "<string>",
    "check_date": "2023-12-25",
    "external_reference": "<string>",
    "notes": "<string>",
    "payment_date": "2023-12-25"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    account_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    amount: 5000,
    auto_apply: true,
    route_unapplied: 'credit',
    applications: [{order_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a', amount_applied: 2500}],
    check_number: '<string>',
    check_date: '2023-12-25',
    external_reference: '<string>',
    notes: '<string>',
    payment_date: '2023-12-25'
  })
};

fetch('https://api.arcuserp.com/v1/payments/multi-invoice-apply', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.arcuserp.com/v1/payments/multi-invoice-apply",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'account_id' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    'amount' => 5000,
    'auto_apply' => true,
    'route_unapplied' => 'credit',
    'applications' => [
        [
                'order_id' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
                'amount_applied' => 2500
        ]
    ],
    'check_number' => '<string>',
    'check_date' => '2023-12-25',
    'external_reference' => '<string>',
    'notes' => '<string>',
    'payment_date' => '2023-12-25'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.arcuserp.com/v1/payments/multi-invoice-apply"

	payload := strings.NewReader("{\n  \"account_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"amount\": 5000,\n  \"auto_apply\": true,\n  \"route_unapplied\": \"credit\",\n  \"applications\": [\n    {\n      \"order_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n      \"amount_applied\": 2500\n    }\n  ],\n  \"check_number\": \"<string>\",\n  \"check_date\": \"2023-12-25\",\n  \"external_reference\": \"<string>\",\n  \"notes\": \"<string>\",\n  \"payment_date\": \"2023-12-25\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.arcuserp.com/v1/payments/multi-invoice-apply")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"account_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"amount\": 5000,\n  \"auto_apply\": true,\n  \"route_unapplied\": \"credit\",\n  \"applications\": [\n    {\n      \"order_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n      \"amount_applied\": 2500\n    }\n  ],\n  \"check_number\": \"<string>\",\n  \"check_date\": \"2023-12-25\",\n  \"external_reference\": \"<string>\",\n  \"notes\": \"<string>\",\n  \"payment_date\": \"2023-12-25\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.arcuserp.com/v1/payments/multi-invoice-apply")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"account_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"amount\": 5000,\n  \"auto_apply\": true,\n  \"route_unapplied\": \"credit\",\n  \"applications\": [\n    {\n      \"order_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n      \"amount_applied\": 2500\n    }\n  ],\n  \"check_number\": \"<string>\",\n  \"check_date\": \"2023-12-25\",\n  \"external_reference\": \"<string>\",\n  \"notes\": \"<string>\",\n  \"payment_date\": \"2023-12-25\"\n}"

response = http.request(request)
puts response.read_body

{
  "data": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "entity_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "amount": 123,
    "payment_method": "<string>",
    "status": "<string>",
    "journal_entry_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "applied_count": 123,
    "applications": [
      {
        "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "order_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "amount_applied": 123
      }
    ]
  },
  "idempotent_replay": true
}

{
  "error": "not_found",
  "code": "not_found",
  "type": "not_found",
  "hint": "The requested order does not exist or does not belong to this entity.",
  "param": "expand[0]",
  "required": "accounts:read",
  "request_id": "req_abc123"
}

{
  "error": "not_found",
  "code": "not_found",
  "type": "not_found",
  "hint": "The requested order does not exist or does not belong to this entity.",
  "param": "expand[0]",
  "required": "accounts:read",
  "request_id": "req_abc123"
}

{
  "error": "not_found",
  "code": "not_found",
  "type": "not_found",
  "hint": "The requested order does not exist or does not belong to this entity.",
  "param": "expand[0]",
  "required": "accounts:read",
  "request_id": "req_abc123"
}

{
  "error": "not_found",
  "code": "not_found",
  "type": "not_found",
  "hint": "The requested order does not exist or does not belong to this entity.",
  "param": "expand[0]",
  "required": "accounts:read",
  "request_id": "req_abc123"
}

Payments

Apply a single payment to multiple invoices (atomic create)

Atomic-create endpoint for multi-invoice AR cash payment application. Accepts a complete payment + applications payload in ONE transactional call. Creates one order_payments row (order_id = NULL) and N order_payment_applications rows. Validates sum(applications[].amount_applied) <= amount within $0.005. Each invoice's balance_due must cover its application. Posts one GL journal entry for the applied portion (DR Cash-equivalent / CR AR). Broadcasts payment.applied_multi_invoice + per-invoice order.payment_status_changed events. Industry standard: NetSuite Customer Payment + Auto Apply, QuickBooks Payment Line[] + unapplied credit, Acumatica AR Document Applications + Auto-Application. Idempotent via Idempotency-Key header. Auto-apply: pass auto_apply=true (and omit applications) to have the server allocate the payment oldest-first across the account open invoices (capped per invoice balance_due). The response returns the computed applications[]. Unapplied cash: if the amount exceeds what the open invoices can absorb, pass route_unapplied='credit' to hold the surplus as a credit-on-account (a balanced DR clearing / CR Customer Credits journal entry posts in the same transaction and the account credit_balance is incremented). Without route_unapplied, a surplus is REFUSED (no silent cap).

POST

payments

multi-invoice-apply

curl --request POST \
  --url https://api.arcuserp.com/v1/payments/multi-invoice-apply \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "account_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "amount": 5000,
  "auto_apply": true,
  "route_unapplied": "credit",
  "applications": [
    {
      "order_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "amount_applied": 2500
    }
  ],
  "check_number": "<string>",
  "check_date": "2023-12-25",
  "external_reference": "<string>",
  "notes": "<string>",
  "payment_date": "2023-12-25"
}
'

import requests

url = "https://api.arcuserp.com/v1/payments/multi-invoice-apply"

payload = {
    "account_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "amount": 5000,
    "auto_apply": True,
    "route_unapplied": "credit",
    "applications": [
        {
            "order_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
            "amount_applied": 2500
        }
    ],
    "check_number": "<string>",
    "check_date": "2023-12-25",
    "external_reference": "<string>",
    "notes": "<string>",
    "payment_date": "2023-12-25"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    account_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    amount: 5000,
    auto_apply: true,
    route_unapplied: 'credit',
    applications: [{order_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a', amount_applied: 2500}],
    check_number: '<string>',
    check_date: '2023-12-25',
    external_reference: '<string>',
    notes: '<string>',
    payment_date: '2023-12-25'
  })
};

fetch('https://api.arcuserp.com/v1/payments/multi-invoice-apply', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.arcuserp.com/v1/payments/multi-invoice-apply",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'account_id' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    'amount' => 5000,
    'auto_apply' => true,
    'route_unapplied' => 'credit',
    'applications' => [
        [
                'order_id' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
                'amount_applied' => 2500
        ]
    ],
    'check_number' => '<string>',
    'check_date' => '2023-12-25',
    'external_reference' => '<string>',
    'notes' => '<string>',
    'payment_date' => '2023-12-25'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.arcuserp.com/v1/payments/multi-invoice-apply"

	payload := strings.NewReader("{\n  \"account_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"amount\": 5000,\n  \"auto_apply\": true,\n  \"route_unapplied\": \"credit\",\n  \"applications\": [\n    {\n      \"order_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n      \"amount_applied\": 2500\n    }\n  ],\n  \"check_number\": \"<string>\",\n  \"check_date\": \"2023-12-25\",\n  \"external_reference\": \"<string>\",\n  \"notes\": \"<string>\",\n  \"payment_date\": \"2023-12-25\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.arcuserp.com/v1/payments/multi-invoice-apply")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"account_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"amount\": 5000,\n  \"auto_apply\": true,\n  \"route_unapplied\": \"credit\",\n  \"applications\": [\n    {\n      \"order_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n      \"amount_applied\": 2500\n    }\n  ],\n  \"check_number\": \"<string>\",\n  \"check_date\": \"2023-12-25\",\n  \"external_reference\": \"<string>\",\n  \"notes\": \"<string>\",\n  \"payment_date\": \"2023-12-25\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.arcuserp.com/v1/payments/multi-invoice-apply")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"account_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"amount\": 5000,\n  \"auto_apply\": true,\n  \"route_unapplied\": \"credit\",\n  \"applications\": [\n    {\n      \"order_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n      \"amount_applied\": 2500\n    }\n  ],\n  \"check_number\": \"<string>\",\n  \"check_date\": \"2023-12-25\",\n  \"external_reference\": \"<string>\",\n  \"notes\": \"<string>\",\n  \"payment_date\": \"2023-12-25\"\n}"

response = http.request(request)
puts response.read_body

{
  "data": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "entity_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "amount": 123,
    "payment_method": "<string>",
    "status": "<string>",
    "journal_entry_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "applied_count": 123,
    "applications": [
      {
        "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "order_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "amount_applied": 123
      }
    ]
  },
  "idempotent_replay": true
}

{
  "error": "not_found",
  "code": "not_found",
  "type": "not_found",
  "hint": "The requested order does not exist or does not belong to this entity.",
  "param": "expand[0]",
  "required": "accounts:read",
  "request_id": "req_abc123"
}

{
  "error": "not_found",
  "code": "not_found",
  "type": "not_found",
  "hint": "The requested order does not exist or does not belong to this entity.",
  "param": "expand[0]",
  "required": "accounts:read",
  "request_id": "req_abc123"
}

{
  "error": "not_found",
  "code": "not_found",
  "type": "not_found",
  "hint": "The requested order does not exist or does not belong to this entity.",
  "param": "expand[0]",
  "required": "accounts:read",
  "request_id": "req_abc123"
}

{
  "error": "not_found",
  "code": "not_found",
  "type": "not_found",
  "hint": "The requested order does not exist or does not belong to this entity.",
  "param": "expand[0]",
  "required": "accounts:read",
  "request_id": "req_abc123"
}

Authorizations

Authorization

string

header

required

API key issued per entity via Settings > Developers > API Keys. Each key carries scopes (e.g. orders:read, products:write). Bearer token format: Authorization: Bearer ark_live_ent_Test keys use ark_test_ent_. Both are issued per entity via Settings > Developers > API Keys.

Headers

Idempotency-Key

string

Client-generated unique key for idempotent POST/PATCH/DELETE operations. Alias for the Idempotency parameter. Max 255 chars. On retry with the same key, the original response is returned without re-executing the operation. Keys expire after 24 hours.

Maximum string length: 255

Body

application/json

account_id

string<uuid>

required

The customer account receiving this payment.

payment_method

enum<string>

required

Tender method for this payment.

Available options:

check,

ach,

wire,

external,

cash,

credit

amount

number

required

Total payment amount in dollars (cash actually received). The sum of applications[].amount_applied must be <= amount; any surplus requires route_unapplied='credit'.

Example:

5000

auto_apply

boolean

When true (and applications omitted), the server allocates the payment oldest-first across the account open invoices. The response returns the computed applications[].

Example:

true

route_unapplied

enum<string>

When 'credit', any surplus (amount beyond what open invoices absorb) is held as a credit-on-account via a balanced journal entry in the same transaction. Without it, a surplus is refused (no silent cap).

Available options:

credit

applications

object[]

Per-invoice application lines (manual override). Omit when auto_apply=true. Sum of amount_applied must be <= amount; any remainder requires route_unapplied='credit'.

Required array length: 1 - 50 elements

Show child attributes

check_number

string

Check number (for check payments).

check_date

string<date>

Check date (YYYY-MM-DD).

external_reference

string

External reference (ACH trace number, wire memo, etc.).

notes

string

Internal notes for this payment.

payment_date

string<date>

Payment date for GL posting (YYYY-MM-DD; defaults to today).

Response

Payment applied successfully

data

object

Show child attributes

idempotent_replay

boolean

Post an atomic multi-line payment batch List open invoices for multi-invoice payment modal