Use BILL webhooks to subscribe to and receive real-time notifications for events, such as create a vendor, update a vendor, or create a payment. In addition, as a BILL partner, when you create a subscription for events, you get event notifications for all your created organizations. ## Tutorial: BILL v3 API webhooks explained

When you subscribe to BILL events, you provide a location URL for where you want to receive notifications. BILL sends a notification to that URL each time a subscribed event is triggered. ## BILL webhooks best practice While the BILL webhooks work as expected, we recommend that webhook notifications should not be treated as the only source of truth. For critical workflows, we recommend validating data with the `GET` API operations for accuracy and consistency. import React, { useState, Children, isValidElement, cloneElement } from "react"; export const Steps = ({ name = "steps", children }) => { const childArray = Children.toArray(children); const count = childArray.length; return (

{childArray.map((child, index) => { if (isValidElement(child)) { return cloneElement(child, { key: index, stepIndex: index, stepsName: name, isFirst: index === 0, isLast: index === count - 1, }); } return child; })}

); }; export const Step = ({ number, stepIndex = 0, title = "", stepsName = "steps", isFirst = false, isLast = false, children, }) => { const [isHovered, setIsHovered] = useState(false); const [copied, setCopied] = useState(false); const displayNumber = number !== undefined ? number : stepIndex + 1; const stepId = `${stepsName}-${displayNumber}`; const copyLink = () => { if (typeof window === 'undefined') return; try { const url = `${window.location.origin}${window.location.pathname}#${stepId}`; navigator.clipboard.writeText(url); setCopied(true); setTimeout(() => setCopied(false), 1500); } catch (error) { console.error('Failed to copy link:', error); } }; return (

{/* Vertical line - positioned behind the number, extends into padding */}

{/* Number button - positioned on top of line */} {/* Right column: title + content */}

{title}

{children}

); }; Use BILL webhooks as a trigger for your system to learn that an entity has changed. Validate data with the `GET` API operation for the entity. For example, when you receive a `vendor.updated` notification, validate with `GET /v3/vendors/{vendorId}`. Maintain an idempotent system that is able to safely handle duplicate event notifications. Set up a cadence (for example, weekly or daily) for data reconciliation. In case a webhook is delayed or missed, your system can detect and fix any drift with the API. ## More documentation In the next set of sections, we walk through the rules for working with BILL webhooks. | Section | Description | | :---------------------------------------------------------------------------------------------------------------------------------------------------- | :---------------------------------------------------------------------------------------------- | | Webhook API general rules | Access rules, authentication rules, and idempotent key rules | | Webhook API notification rules | BILL webhook notifications for events follow a set of rules | | Webhook Events and Subscriptions | Subscribe to BILL events, generate a test event notification, and get events for a subscription | | Test with BILL webhook security | Steps for validating the BILL webhook security measures | | Webhook API error responses | For error responses, BILL sends an HTTP status code depending on the error | In addition, we list examples of the BILL webhook events and notification payloads in the Notification payloads reference. | Event | Related documentation | | :---------------------------------------------------------------------------------------------------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `vendor.created`
`vendor.updated`
`vendor.archived`
`vendor.restored` | Vendor notification payloads | | `autopay.failed` | Vendor auto-pay notification payload | | `bill.created`
`bill.updated`
`bill.archived`
`bill.restored` | AP bill notification payloads | | `payment.updated`
`payment.failed` | AP payment notification payloads | | `bank-account.created`
`bank-account.updated` | Bank account notification payloads | | `card-account.created`
`card-account.updated` | Card account notification payloads | | `invoice.created`
`invoice.updated`
`invoice.archived`
`invoice.restored` | AR invoice notification payloads | | `risk-verification.updated` | Risk verification notification payload | | `spend.transaction.updated` | Spend & Expense transaction notification payload | | `spend.reimbursement.created`
`spend.reimbursement.updated`
`spend.reimbursement.deleted` | Spend & Expense reimbursement notification payload | | `spend.three-ds-challenge.created` | Spend & Expense 3D Secure challenge notification payload |