Create a Payment from a Bill

https://api.constructiononline.com/api/COLPayments?billID={id}

This endpoint allows users to create a new payment for a bill in their ConstructionOnline company account. If successful, the endpoint will return a record of the newly created payment. The new payment will be automatically assigned a unique numerical ID called 'ID', which will be used for any future references. The required fields for this endpoint include billID; all other properties are optional and can be entered during purchase order creation.

Requests
Responses

Requests

Required Parameters:

billID: integer
- Unique Identifier for the Bill.

Additional Parameters:

percent: integer
- Percentage of the total bill amount to include in the created payment.
- If `percent` is not provided, the value defaults to `100`. If `percent` is less than `0` or greater than `100`, the value also defaults to `100`.
title: string
- Unique title for the created payment. If `title` is not provided, the value defaults to `"Payment# {project_ID}-{###}"`.

Sample URL Request:

https://api.constructiononline.com/api/COLPayments?billID=2608&percent=25&title="Sub Payment #1"

Example requests in cURL, C#, Python, and JavaScript can be found below:

cURL

# replace {email} with the email address for your ConstructionOnline account
# {password} with your ConstructionOnline password
# {apikey} with your provided API key
# {id} with the bill's ID

curl -X POST https://api.constructiononline.com/api/COLPayments?billID={id} -u {email}:{password} -H 'APIKey:{apikey}'

/* replace {username} with the email address for your ConstructionOnline account
           {password} with your ConstructionOnline password
           {apikey} with your provided API key 
           {id} with the bill's ID */
        

public string MakeRequest(string endpoint, string payload) {
     string username = {username};
     string password = {password};
     string apiKey = {apikey};
     string response = "";
      var handler = new HttpClientHandler() { AutomaticDecompression = System.Net.DecompressionMethods.GZip };
          using (HttpClient client = new HttpClient(handler)) {
           client.BaseAddress = new Uri("http://api.constructiononline.com");
           client.DefaultRequestHeaders.Accept.Clear();
           client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
           client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", System.Convert.ToBase64String(System.Text.Encoding.GetEncoding("ISO-8859-1").GetBytes(username + ":" + password)));
           client.DefaultRequestHeaders.Add("APIKey", apiKey);
           client.DefaultRequestHeaders.Add("Accept-Encoding", "gzip");
           HttpContent content = new StringContent(payload, System.Text.Encoding.UTF32, "application/json");
           response = client.PostAsync(endpoint, content).Result.ToString();
            }
      return response;
            }

     MakeRequest("api/COLPayments?billID={id}");

Python

#replace {username} with the email address for your ConstructionOnline account
#{password} with your ConstructionOnline password
#{apikey} with your provided API key
#{id} with the bill's ID


import base64, requests, json
#Global Variables
  apikey = {apikey}
  username = {username}
  password = {password}

#Functions
  def makeRequest(endpoint, payload):
       url = "https://api.constructiononline.com/" + endpoint
       userPass = username + ":" + password    
       headers = {
                    "APIKey": apikey,
                    "Accept-Encoding": "gzip, deflate, br",
                    "Authorization": "Basic " + base64.b64encode(userPass.encode()).decode(),
                }
       response = requests.request("POST", url, headers=headers, data=payload)
       return json.dumps(json.loads(response.text), indent=2)   
#Main Program 
print(makeRequest("api/COLPayments?billID={id}"))

JavaScript

/* replace {username} with the email address for your ConstructionOnline account
           {password} with your ConstructionOnline password
           {apikey} with your provided API key 
           {id} with the bill's ID */
     

 username = '{username}';
 password = '{password}';
 apikey = '{apikey}';

 function makeRequest(endpoint, payload) {
          auth = btoa('${username}:${password}');
          var myHeaders = new Headers();
          myHeaders.append("APIKey", apikey);
          myHeaders.append("Accept-Encoding", "gzip, deflate, br");
          myHeaders.append("Authorization", "Basic ${auth}");

                var requestOptions = {
                    method: 'POST',
                    body: '',
                    headers: myHeaders,
                    redirect: 'follow'
                };
                fetch("https://api.constructiononline.com/" + endpoint, requestOptions)
                    .then(response => response.text())
                    .then(result => console.log(result))
                    .catch(error => console.log('error', error));
                return response;
            };
 makeRequest("api/COLPayments?billID={id}");

Responses

200: Success

A successful request will return a 200 response with a record of the newly created payment in the body, as seen below.

{
    "ID": 32118,
    "TITLE": "Payment# 1340167-022",
    "NUMBER": "1340167-022",
    "COMPANY_ID": 23573,
    "PRJ_ID": 1340167,
    "ESTIMATE_ID": 516390,
    "VENDOR_ID": 885048,
    "PAID_DATE": null,
    "DATE_CREATED": "2026-11-04T15:47:22.647",
    "CREATED_BY": 885048,
    "SUBTOTAL": 3975.0,
    "TOTAL": 4551.375,
    "LMOD": "2026-11-04T15:47:22.647",
    "LMOD_BY": 885048,
    "NOTES": "",
    "PAYMENT_METHOD": 0,
    "TRAFFIC_COLOR": 0,
    "ACCT_INT_ID": 0,
    "ACCT_INT_VENDOR_ID": 0,
    "SENT_TO_ACCT_INT_VALUE": 0.0,
    "ACCT_INT_SENT_AS": null,
    "SENT_TO_ACCT_INT_DATE": null,
    "SENT_TO_ACCT_INT_BY": null,
    "ITEMS": [
        {
            "ID": 158958,
            "PAYMENT_ID": 32118,
            "ITEM_ID": 365669,
            "AMOUNT": 23804.06
        }
    ]
}

404: Error

The server was not able to locate the resource specified in the request.

429: Error

The user has surpassed the request rate limit for the hour, day, week, or month.

500: Error

There was an internal server error and the server was unable to complete the request.

Last updated: Sep 29, 2026

Create a Payment from a Bill

Generate a new payment from a bill within your ConstructionOnline company account

Requests

Responses