Update a purchase order

curl --request PATCH \
  --url https://api.arcuserp.com/v1/purchase-orders/{id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "expected_date": "2023-12-25",
  "notes": "<string>",
  "payment_term_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "location_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "vendor_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "status": "<string>"
}
'

import requests

url = "https://api.arcuserp.com/v1/purchase-orders/{id}"

payload = {
    "expected_date": "2023-12-25",
    "notes": "<string>",
    "payment_term_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "location_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "vendor_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "status": "<string>"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'PATCH',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    expected_date: '2023-12-25',
    notes: '<string>',
    payment_term_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    location_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    vendor_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    status: '<string>'
  })
};

fetch('https://api.arcuserp.com/v1/purchase-orders/{id}', 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/purchase-orders/{id}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PATCH",
  CURLOPT_POSTFIELDS => json_encode([
    'expected_date' => '2023-12-25',
    'notes' => '<string>',
    'payment_term_id' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    'location_id' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    'vendor_id' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    'status' => '<string>'
  ]),
  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/purchase-orders/{id}"

	payload := strings.NewReader("{\n  \"expected_date\": \"2023-12-25\",\n  \"notes\": \"<string>\",\n  \"payment_term_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"location_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"vendor_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"status\": \"<string>\"\n}")

	req, _ := http.NewRequest("PATCH", 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.patch("https://api.arcuserp.com/v1/purchase-orders/{id}")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"expected_date\": \"2023-12-25\",\n  \"notes\": \"<string>\",\n  \"payment_term_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"location_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"vendor_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"status\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.arcuserp.com/v1/purchase-orders/{id}")

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

request = Net::HTTP::Patch.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"expected_date\": \"2023-12-25\",\n  \"notes\": \"<string>\",\n  \"payment_term_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"location_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"vendor_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"status\": \"<string>\"\n}"

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

{
  "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "object": "purchase_order",
  "entity_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "po_number": "<string>",
  "vendor_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "location_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "status": "draft",
  "po_date": "2023-11-07T05:31:56Z",
  "expected_date": "2023-11-07T05:31:56Z",
  "subtotal": 123,
  "tax_total": 123,
  "shipping_total": 123,
  "po_total": 123,
  "currency": "USD",
  "notes": "<string>",
  "internal_notes": "<string>",
  "metadata": {},
  "created_at": "2023-11-07T05:31:56Z",
  "updated_at": "2023-11-07T05:31:56Z",
  "approved_total": 123,
  "approval_stale": true,
  "header_editability": {}
}

{
  "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"
}

Purchasing

Update a purchase order

Updates header-level fields on a purchase order (delivery date, payment due date, receiving location, tracking reference, notes, internal notes). Line items are updated via the items sub-resource.

Editability by stage (2026-08-17). The four OPERATIONAL fields (expected_date, due_date, location_id, po_tracking_reference) are editable while the purchase order is draft, open or processing. On fulfilled and cancelled only notes and internal_notes remain writable, as an annotation. On archived and expired nothing is writable. While approval_status is pending only internal_notes is writable. Any other status is treated as locked (fail-closed). A request that touches a blocked field is refused WHOLE with 422 and the response names the offending fields in blocked_fields; nothing is partially applied. Reason codes: po_status_locked, po_status_unknown_locked, notes_only_on_terminal, po_pending_approval_edit_locked, po_pending_approval_and_terminal.

NOTE: the previous version of this description claimed header edits were limited to status: draft and that “orders in approved or later status require a change-order flow”. Neither was true — this handler had no status gate at all, and approved / sent are not members of the real order_status vocabulary (draft / open / processing / fulfilled / cancelled / archived / expired).

Requires purchasing:write scope.

Drop-ship destination (2026-07-10). shipping_address_id is writable ONLY on a drop-ship-linked PO (a sales-order line sources from it) that is unsent and unreceived; otherwise 422 po_shipto_not_editable, 409 dropship_po_sent_blocks_shipto_change (change it on the parent sales order with propagate_to_sent_pos: true instead), or 409 dropship_po_received_blocks_shipto_change. The address must belong to the entity.

PATCH

purchase-orders

{id}

Update a purchase order

curl --request PATCH \
  --url https://api.arcuserp.com/v1/purchase-orders/{id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "expected_date": "2023-12-25",
  "notes": "<string>",
  "payment_term_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "location_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "vendor_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "status": "<string>"
}
'

import requests

url = "https://api.arcuserp.com/v1/purchase-orders/{id}"

payload = {
    "expected_date": "2023-12-25",
    "notes": "<string>",
    "payment_term_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "location_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "vendor_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "status": "<string>"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'PATCH',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    expected_date: '2023-12-25',
    notes: '<string>',
    payment_term_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    location_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    vendor_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    status: '<string>'
  })
};

fetch('https://api.arcuserp.com/v1/purchase-orders/{id}', 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/purchase-orders/{id}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PATCH",
  CURLOPT_POSTFIELDS => json_encode([
    'expected_date' => '2023-12-25',
    'notes' => '<string>',
    'payment_term_id' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    'location_id' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    'vendor_id' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    'status' => '<string>'
  ]),
  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/purchase-orders/{id}"

	payload := strings.NewReader("{\n  \"expected_date\": \"2023-12-25\",\n  \"notes\": \"<string>\",\n  \"payment_term_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"location_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"vendor_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"status\": \"<string>\"\n}")

	req, _ := http.NewRequest("PATCH", 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.patch("https://api.arcuserp.com/v1/purchase-orders/{id}")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"expected_date\": \"2023-12-25\",\n  \"notes\": \"<string>\",\n  \"payment_term_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"location_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"vendor_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"status\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.arcuserp.com/v1/purchase-orders/{id}")

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

request = Net::HTTP::Patch.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"expected_date\": \"2023-12-25\",\n  \"notes\": \"<string>\",\n  \"payment_term_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"location_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"vendor_id\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"status\": \"<string>\"\n}"

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

{
  "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "object": "purchase_order",
  "entity_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "po_number": "<string>",
  "vendor_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "location_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "status": "draft",
  "po_date": "2023-11-07T05:31:56Z",
  "expected_date": "2023-11-07T05:31:56Z",
  "subtotal": 123,
  "tax_total": 123,
  "shipping_total": 123,
  "po_total": 123,
  "currency": "USD",
  "notes": "<string>",
  "internal_notes": "<string>",
  "metadata": {},
  "created_at": "2023-11-07T05:31:56Z",
  "updated_at": "2023-11-07T05:31:56Z",
  "approved_total": 123,
  "approval_stale": true,
  "header_editability": {}
}

{
  "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.

Path Parameters

string

required

Purchase order UUID or PO number (e.g. PO-001234). Polymorphic lookup: if the value is not a UUID it is resolved to a UUID via orders.order_number where document_type=purchase_order within the entity scope. (NEW-GAP-API-V1-POLYMORPHIC-LOOKUP-CROSS-RESOURCE 2026-05-20)

Body

application/json

expected_date

string<date>

notes

string

payment_term_id

string<uuid>

location_id

string<uuid>

vendor_id

string<uuid>

status

string

Response

Updated purchase order

A purchase order issued to a vendor.

string<uuid>

object

enum<string>

Available options:

purchase_order

entity_id

string<uuid>

read-only

po_number

string

read-only

vendor_id

string<uuid>

location_id

string<uuid> | null

status

enum<string>

read-only

Available options:

draft,

approved,

sent,

partially_received,

received,

closed,

cancelled

po_date

string<date-time>

expected_date

string<date-time> | null

subtotal

number

tax_total

number

shipping_total

number

po_total

number

currency

string

default:USD

notes

string | null

internal_notes

string | null

metadata

object | null

created_at

string<date-time>

read-only

updated_at

string<date-time>

read-only

approved_total

number | null

read-only

The order total as it stood when an approver approved this purchase order -- the basis they actually saw. NULL on every approval predating 2026-08-17 (no backfill) and NULL means "basis unknown", which is treated as fail-safe.

approval_stale

boolean

read-only

DERIVED, not stored. True when the order is approved AND its total has since risen above approved_total. The purchase order still receives normally; this is a non-blocking prompt to re-approve.

header_editability

object

read-only

Per-field verdicts for the header fields, from the same predicate the write handlers enforce. Keys: notes, internal_notes, due_date, expected_date, location_id, po_tracking_reference. Each is { allowed: boolean, reason: string|null } where reason is a token from the PoLineEditReason vocabulary.

Show child attributes

Overview

All Endpoints

Update a purchase order

Authorizations

Path Parameters

Body

Response