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An accounts payable internal controls checklist for businesses

An accounts payable internal controls checklist for businesses

Emily Taylor
Contributing writer, BILL
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Accounting teams depend on internal controls to mitigate the risk of AP fraud while ensuring efficiency and accuracy throughout their accounts payable (AP) processes.

With effective AP internal controls in place, your team can help your organization prevent fraud, reduce errors, and ensure regulatory compliance—all while helping you safely delegate financial responsibilities across your finance and accounting teams.

This post provides an accounts payable internal control checklist that can help strengthen your payment processes.

Types of accounts payable internal controls

1. Obligation-to-pay controls

Obligation-to-pay controls help make sure your company is only paying amounts that it is, in fact, obligated to pay. They're designed to catch inaccuracies, duplications, and even outright fraud in your incoming invoices.

Purchase order approval

Establish a formal process for approving purchase orders to help you track upcoming spending and prevent excessive cash outflow. To request goods or services, individuals or departments can fill out purchase requisition forms, which are then reviewed and approved by the procurement department.

Pro tip: You can require purchase orders only above a certain amount to lower the number of hours this requires from your team, or simply use a spend automation tool like BILL Spend & Expense to set budgets ahead of time.

Invoice approval

Put a standard approval system in place to verify the validity and accuracy of supplier invoices before you process payments. Authorized approvers should review and approve invoices based on the goods and services actually received as well as agreed-upon pricing. Approvers do this by checking invoice items and amounts against purchase orders, packing lists, contracts, or other relevant documents.

Pro tip: In a strong approval system, approvers should be close to the goods and services received. Generally, they are not part of the accounting team but rather the department heads or managers who requested the goods or services that were delivered.

Invoice validation (3-way matching)

Use a 3-way matching process to ensure invoices match purchase orders, receiving information, and inspection records. This helps verify that the goods or services have been received as expected before authorizing payment.

Pro tip: Counting on busy approvers to apply perfect 3-way matching every time leaves something to be desired. Instead, standardize your 3-way matching with an automation platform that can streamline the process while ensuring that it's followed. 

Duplicate search

Check each invoice as it comes in against your accounts payable and payment records to identify and prevent duplicate payments. This requires keeping your financial records up to date—in real time. Otherwise, your team could be checking its duplicate invoice or duplicate payment search against a list that doesn't yet include invoices you've received or payments you've already made.

Pro tip: Consider using an AP automation platform like BILL Accounts Payable that can automatically flag duplicate invoices, minimizing the risk of erroneous payments.

2. Data entry controls

As invoices are approved, they need to be entered into your AP system. Data entry controls help ensure that errors aren't introduced during this step.

Data entry standardization

First, establish clear, standardized processes for recording invoice data in the accounts payable system. This helps ensure consistency and accuracy in data entry, reducing the risk of errors.

Pro tip: Because invoices may arrive in different ways, such as by mail or via different email addresses, creating a standard process can be a challenge. If you're considering an automation platform, be sure it can read invoices and enter that data for you whether the bill arrives by email, by PDF scan, or even by photo snapped on a phone.

Double-check data entry

Create quality control guidelines for checking data entry after the fact, to help catch any errors that might have been introduced. A specific checklist can help drive attention toward key details, such as invoice number, amount, date, and terms.

Pro tip: If you're using an automation platform, make sure it includes OCR (optical character recognition) to read each invoice and enter it for you. Let automation take care of the first round of entry, and use human intelligence for quality control.

3. Payment controls

When it's time to pay each invoice, payment controls help increase the security of your payment process.

Secure check storage

Store physical checks in a secure and locked location to prevent unauthorized access and fraud. Additionally, keep signature plates and stamps in a secure place to minimize the risk of unauthorized usage.

Pro tip: Some payment services use clearing accounts to write physical checks for you, so there's no need to store physical check stock—or to expose your own banking information on your checks.

Separation of duties

Also known as segregation of duties, separation of duties in payments requires assigning various payment tasks to different staff members. For example, one person can prepare checks while another person signs them. This reduces the risk of fraud by ensuring that a single individual doesn't control the entire accounts payable process.

Pro tip: Consider using technology rather than a manual accounts payable process to ensure that payment controls such as separation of duties are followed in practice. Assigning roles and unique logins makes it far more difficult to cut corners when it comes to internal controls.

Check number sequence tracking

Keep a log of all check numbers and amounts issued to identify any missing checks, duplicate payments, or potential payment errors. 

Pro tip: If you're using a payment platform to write physical checks, ask whether the platform uses Positive Pay as an added security measure.

Check signing procedures

Sign checks manually rather than relying on signature stamps. Also, consider implementing a double signing process for checks over a certain amount to enhance security and reduce the risk of fraudulent activity.

Pro tip: Be sure your payment automation platform supports custom approval rules so you can require dual approvals for higher-risk transactions—whether paying by ACH, check, credit card, or wire transfer.

Vendor payment information updates

When sensitive vendor information, such as account numbers or addresses, changes, take steps to verify and confirm the accuracy of the updated information. This helps prevent fraudulent activities and ensures secure payments.

Pro tip: Consider a payment platform with a network that lets vendors update and maintain their own information. This ensures accurate, up-to-date information while removing the time requirement from your team.

4. Fraud controls

Fraud controls are just what they sound like in your AP process—they help protect your company from fraud. While many of the controls above also help prevent fraud, there's at least one more to be aware of.

Record after approval

Record invoices in your AP system only after they've been approved by authorized personnel. This prevents errors and ensures that your invoice data is accurate and valid.

Pro tip: In a manual AP process, making sure that potentially fraudulent invoices haven't been entered into your system requires regular AP audits. By automating your approval, invoice entry, and payment processes—and limiting edit access to your accounting software—new invoices are forced to go through proper controls, reducing the chance of fraud and unauthorized payments.

Automate internal controls in your accounts payable process with BILL

​​“The controls that BILL has in place are the unsung heroes for our firm!” —Redmond Accounting, a Menlo Park–based firm and BILL customer since 2010.

Using BILL to automate your AP processes can help you make sure these AP internal controls are solidly in place—and that they're being used consistently.

BILL helps you enforce internal controls in your accounts payable processes with role-based user permissions, custom approval rules, an audit trail that logs every touchpoint, and more—making sure your internal control systems are applied automatically.

To learn more, visit our BILL page on accounts payable controls

Internal controls in accounts payable FAQs

What are the types of accounts payable internal controls?

Accounts payable internal controls can be categorized into obligation-to-pay controls, data entry controls, payment controls, and fraud controls, as shown in the lists above. For more information, download "A complete guide to AP internal controls.”

Why are internal controls important for accounts payable optimization?

Internal controls are important for accounts payable optimization because they help ensure payment accuracy, prevent fraud, minimize errors, and ensure compliance with regulatory requirements.

Need to apply internal controls for a remote AP department? Learn how in our free on-demand webinar "Adapting Internal Controls for Distributed AP Teams."

How does automation enhance accounts payable controls?

Automation enhances accounts payable controls by streamlining processes, reducing manual data entry, improving accuracy, and providing better visibility into payment workflows. It also enables the use of system-based checks and balances, minimizing the risk of errors and fraud by ensuring that invoices and payments flow through the system of internal controls that have been incorporated into the platform.

Learn more in our free, on-demand webinar "9 Frequently-Overlooked AP Internal Control Issues: How to Prevent Them."

Author
Emily Taylor
Contributing writer, BILL
With a background in finance and over a decade of experience in business writing, Emily simplifies complex finance topics to help businesses streamline operations, manage cash flow, and make smarter financial decisions.
Author
Emily Taylor
Contributing writer, BILL
With a background in finance and over a decade of experience in business writing, Emily simplifies complex finance topics to help businesses streamline operations, manage cash flow, and make smarter financial decisions.
Get more from BILL
Subscribe to finance insights and thought leadership content delivered straight to your inbox.
By continuing, you agree to BILL's Terms of Service and Privacy Notice.

Frequently asked questions

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Software Comparison

BILL Spend & Expense
Best for AI expense automation
4.5 on G2
  • Smart corporate cards with real-time tracking, flexible limits, and instant visibility into every transaction across your team [1]
  • Unlimited free virtual cards with unique numbers for each vendor or subscription—freeze, delete, or set custom limits instantly to prevent overcharges and reduce fraud risk [5]
  • AI-powered auto-categorization and receipt matching that connects card transactions and expenses into a single reconciliation workflow [1]
  • Customizable budgets with spend controls based on merchant, amount, receipt requirements, and configurable approval workflows [3]
  • Auto-freeze on cards with incomplete transactions, ensuring receipts and documentation are captured before additional spend is approved [1]
  • Up to 7x points on restaurants, 5x on hotels, 2x on recurring software, and 1.5x on all other purchases (rates shown are for weekly or daily billing cycle; rates vary by billing frequency) [2]
  • Two-way sync with QuickBooks, NetSuite, Sage Intacct, Xero, and Microsoft Dynamics; additional integrations with Acumatica, Slack, and HRIS platforms [1]
  • Pro: $0/user/month with all features included—no paid tier to unlock [4]
  • Pro: Merchant controls and auto-freeze cards at no extra cost [1]
  • Pro: Credit lines that don't fluctuate daily based on bank balance [4]
  • Pro: All ERP integrations (NetSuite, Sage Intacct, Xero) included free [1]
  • Con: 12-month holding period before rewards can be redeemed [2]
  • Con: Category reward multipliers cap at $5,000/month per category [2]
  • Con: Less established in global, enterprise-scale expense programs with multi-country regulatory requirements

BILL Spend & Expense pairs corporate cards with AI-powered expense management and budget controls in a single platform at no cost—teams aren't paying per user or upgrading to unlock features that competitors gate behind paid tiers.

Merchant-level spend controls and auto-freeze on incomplete transactions give admins granular oversight without manual policing, and two-way ERP integrations are included free where Ramp and Brex charge for NetSuite and Sage Intacct access. The main trade-off is an initial 12-month rewards holding period before accumulated points can be redeemed. [1][2][3][4]

Commonly compared to: Ramp and Brex (for card-first expense management), and SAP Concur (for enterprise expense programs).

Pricing
$0/user/month with no annual fee
Integrations
Two-way sync with QuickBooks, NetSuite, Sage Intacct, Xero, and Microsoft
Ideal company size
SMB to mid-market
SAP Concur
Best for large enterprises
4 on G2
  • AI-powered receipt capture via ExpenseIt on the SAP Concur mobile app, with smart matching that combines credit card charges and e-receipts into expense reports automatically [7]
  • Configurable approval workflows with built-in audit rules that flag policy exceptions, plus optional Intelligent Audit and Verify add-ons for automated compliance checks [6][7]
  • Modular product suite: Concur Expense, Concur Travel, and Concur Invoice are separate products that can be purchased individually or together, so organizations can start with expense management and add capabilities over time [6]
  • Bank card feed integrations that import corporate card transactions directly into expense reports for automatic reconciliation [6]
  • Joule, SAP's AI assistant, for expense report review, spend analysis, and cost estimation [6]
  • Budget tracking and monitoring tools that give finance teams visibility into spend against departmental or project-level budgets [6]
  • Support for global operations with multi-currency expense reporting and country-specific tax and regulatory compliance tools [6]
  • Pro: 300+ pre-built integrations including native SAP ERP sync [7][8]
  • Pro: Global coverage with multi-currency and regulatory compliance tools [6]
  • Pro: Modular—add travel or invoice management without switching platforms [6]
  • Pro: AI-powered receipt capture and smart matching via ExpenseIt [7]
  • Con: Quote-based pricing; no published rates on the website [6]
  • Con: No corporate card offering; relies on bank card feed integrations [6]
  • Con: Implementation can be complex for smaller organizations [6]
  • Con: Live support requires purchasing the User Support Desk service [6]

SAP Concur is the incumbent in expense management software, with the largest partner ecosystem and broadest global footprint on this list. Its modular approach gives large organizations flexibility to start with expense management and layer on travel or invoice capabilities independently.

The trade-off is complexity—pricing is opaque, there's no corporate card offering, and smaller teams may find the platform more than they need. Organizations already in the SAP ecosystem will get the most value from native S/4HANA integration. [6][7][8]

Commonly compared to: BILL (for SMB expense management), and Coupa (for enterprise spend management).

  • Best for: Mid-market and enterprise organizations that need a globally scalable expense management platform with configurable compliance tools and a large partner ecosystem. [6][7][8]
  • Highlights: AI-powered receipt capture via ExpenseIt, configurable approval workflows with built-in audit rules, optional Intelligent Audit and Verify add-ons for automated compliance checks, 300+ app integrations, and native SAP ERP sync. [6][7][8]
  • Ideal if you need: An expense platform that integrates natively with SAP S/4HANA or other enterprise ERPs, with the flexibility to add modules like Concur Travel or Concur Invoice over time. [6][7]
Pricing
Quote-based
Integrations
QuickBooks, Xero, Sage,TSheets, Gusto, & most business credit cards.
Ideal Company Size
Mid-market to enterprise
Ramp
Best for a broad spend platform
4.8 on G2
  • Corporate cards with customizable spend controls by merchant, category, employee, or department, plus unlimited virtual and physical cards [9][10]
  • AI-powered receipt matching, transaction coding, and memo suggestions that auto-populate as soon as a card is swiped [9]
  • Policy agent that reviews every expense against company policy, auto-approves compliant transactions, and escalates only exceptions with full audit trail [9]
  • Expense submission via SMS, Slack, or Microsoft Teams in addition to web and mobile app [9]
  • Reimbursements for out-of-pocket expenses paid to employees' bank accounts in 1–2 business days [9]
  • Real-time spend reporting with custom dashboards, natural-language queries, and proactive overspend alerts [9]
  • Broader spend platform that includes AP automation, procurement, vendor management, and treasury alongside expense management [9]
  • Pro: Free plan includes corporate cards, expenses, and bill pay [11]
  • Pro: AI policy agent reviews 100% of expenses automatically [9]
  • Pro: Submit expenses via SMS, Slack, or Teams—no app required [9]
  • Pro: Broader spend platform covers AP, procurement, and vendor management [9]
  • Con: Budget tracking requires Ramp Plus at $15/user/month [11]
  • Con: NetSuite, Sage Intacct, and Dynamics integrations require a paid plan [11]
  • Con: HRIS syncs and auto-lock cards require a paid plan [11]
  • Con: Credit limits fluctuate daily based on connected bank balance [12]

Ramp's strength is breadth—it's not just an expense tool but a full spend management platform that includes AP automation, procurement, and vendor management alongside expenses. The AI policy agent is a differentiator, reviewing every transaction against company rules rather than relying on manual manager approvals.

The trade-off is that several features mid-market teams rely on—budget tracking, ERP integrations beyond QuickBooks and Xero, and HRIS syncs—require upgrading to Ramp Plus at $15/user/month plus a platform fee. [9][11]

Commonly compared to: Brex and BILL (for corporate cards and expense management), and SAP Concur (for enterprise expense programs).

  • Best for: Fast-growing companies that want corporate cards, expense management, and accounts payable on a single platform with AI-powered automation. [9][10]
  • Highlights: Corporate cards with built-in spend controls, AI-powered receipt matching and expense coding, a policy agent that reviews 100% of expenses and flags only exceptions, and submission via SMS, Slack, or Microsoft Teams. [9][10]
  • Ideal if you need: A card-first platform where expense management is one part of a larger system that also covers AP, procurement, and vendor management. [9]
Pricing
$0/user/month
Integrations
QuickBooks, NetSuite, Xero, Sage Intacct, Slack, & 100+ accounting tools.
Ideal Company Size
Startups to mid-market
Brex
Best for global teams
4.8 on G2
  • Corporate cards with customizable spend limits by role, department, or category, plus auto-approve for in-policy expenses and auto-decline for out-of-policy spend [13][14]
  • AI-powered expense reviews that auto-approve compliant transactions and surface only exceptions for human review, with clear visibility into why a transaction is flagged [13]
  • Auto-generated receipts and memos with OCR that matches receipts in any language or currency, plus automatic GL coding by department, project, and entity [13]
  • Live Budgets that let department heads set top-level budgets, provision spend to individuals or teams, and track usage in real time with anomaly detection [13]
  • Global reimbursements in 70+ countries in employees' local currency, with subsidiaries able to issue reimbursements from local bank accounts [13]
  • Expense submission and approval via Slack and WhatsApp, with in-app commenting on individual transactions [13]
  • Broader financial platform that includes bill pay, business banking with up to 3.68% yield, and treasury alongside expense management [14]
  • Pro: Free plan includes corporate cards, expenses, bill pay, and travel [15]
  • Pro: AI expense reviews with 99% average policy compliance rate [14]
  • Pro: Global reimbursements in 70+ countries in local currency [13]
  • Pro: Live Budgets with real-time tracking and anomaly detection [13]
  • Con: Live Budgets require Premium at $12/user/month [15]
  • Con: HRIS syncs and customizable ERP integrations require a paid plan [15]
  • Con: Credit limits fluctuate daily based on connected bank balance [16]
  • Con: Multiple expense policies and dynamic review chains require Premium [15]

Brex positions itself as a full financial stack for startups—cards, expenses, banking, and treasury in one platform. The AI expense reviews and 99% average compliance rate (per Brex's internal metrics) are notable, and the global reimbursement coverage across 70+ countries is broader than most competitors on this list.

Like Ramp, Brex gates budget management and HRIS integrations behind a paid tier, and credit limits fluctuate daily based on your bank balance. Teams that need predictable spending power or are past the startup stage may find the pricing structure adds up. [13][14][15]

Commonly compared to: Ramp and BILL (for corporate cards and expense management), and SAP Concur (for enterprise expense programs).

  • Best for: Startups and high-growth companies that want a global financial platform covering corporate cards, expense management, bill pay, and business banking. [13][14]
  • Highlights: AI-powered expense reviews that auto-approve compliant transactions, corporate cards with built-in policy controls, Live Budgets for real-time tracking, global reimbursements in 70+ countries, and OCR receipt matching in any language or currency. [13][14]
  • Ideal if you need: A financial platform built for startups that includes expense management as part of a broader stack with banking, treasury, and AP. [13][14]
Pricing
$0/user/month
Integrations
NetSuite, QuickBooks, Workday,SAP Concur, Slack, & global banking portals.
Ideal Company Size
Startups to mid-market
Expensify
Best for simple reimbursements
4.5 on G2
  • SmartScan receipt capture by photo, email forwarding (receipts@expensify.com), or text message; auto-extracts transaction details and categorizes expenses [17]
  • Bring-your-own-card support: link existing corporate cards from 10,000+ banks globally for automatic reconciliation without switching card providers [17]
  • Expensify Visa Commercial Card with cash back on US purchases; cash back first offsets the Expensify subscription cost, then flows to the company's bank account [17]
  • Concierge AI for automated expense categorization, policy violation flagging, rule enforcement, and error reduction [17]
  • Global reimbursements for employees and independent contractors in their local currency [17]
  • Chat-based collaboration directly on individual expenses to resolve questions in real time rather than through email follow-ups [17]
  • 45+ integrations including QuickBooks, NetSuite, Sage Intacct, Xero, Workday, and Gusto [17]
  • Pro: Bring-your-own-card from 10,000+ banks globally [17]
  • Pro: Expensify Card cash back can offset the subscription cost [17]
  • Pro: SmartScan receipt capture by photo, email, or text message [17]
  • Pro: 45+ integrations including major ERPs and payroll systems [17]
  • Con: No free plan; starts at $5/user/month [18]
  • Con: Pricing structure varies by card spend volume [18]
  • Con: Budget management, advanced approvals, and expense policies require Collect or Control plans [17]
  • Con: No department-level budget management on par with card-first platforms

Expensify's strength is accessibility—it has the lowest barrier to entry for teams that just need to start tracking expenses and submitting receipts. The bring-your-own-card support from 10,000+ banks means companies don't have to switch card providers, and the SmartScan receipt capture (by photo, email, or text) is one of the more flexible input methods on this list.

The trade-off is that several features mid-market teams expect—budget management, advanced approvals, and expense policies—require upgrading to the Collect or Control plans, and spend controls are primarily limited to the Expensify Card rather than extending across all connected cards. [17][18]

Commonly compared to: Zoho Expense (for budget-friendly expense management), and BILL and Ramp (for integrated cards and expenses).

  • Best for: Small and midsize businesses that want a mobile-first expense management tool with flexible card options, including the ability to link existing corporate cards from 10,000+ banks. [17]
  • Highlights: SmartScan receipt capture by photo, email, or text message; bring-your-own-card support from 10,000+ banks globally; Expensify Visa Commercial Card with cash back that offsets subscription costs; and Concierge AI for automated categorization and policy enforcement. [17]
  • Ideal if you need: A lower-cost entry point for expense management where employees can start submitting receipts immediately without switching corporate card providers. [17]
Pricing
From $5/user/month
Integrations
QuickBooks, Xero, Sage, TSheets, Gusto, & most business credit cards.
Ideal Company Size
Small to mid-market
Zoho Expense
Best for budget-conscious teams
4.5 on G2
  • Autoscan receipt capture with OCR that auto-categorizes and itemizes each expense, plus the ability to split or tag expenses across departments, projects, or cost centers [19][20]
  • Automated per diem calculations with pre-defined rules based on country, location, and trip details for regional compliance [20]
  • Corporate card management with real-time feeds that automatically match transactions to uploaded receipts for faster reconciliation [20]
  • Mileage tracking with four input methods across Android, iPhone, and Apple Watch [20]
  • Configurable approval workflows, expense policies, and audit rules with detailed audit trails for compliance [19][20]
  • Custom modules, workflow automation, webhooks, and configurable UI elements for businesses that need tailored expense processes [19]
  • Active-user pricing model: only employees who actually create expenses are charged, so admins and approvers who don't submit reports are free [21]
  • Pro: Free plan available for up to 3 users with core expense tracking [21]
  • Pro: Active-user pricing—admins and approvers aren't charged [21]
  • Pro: Automated per diem calculations by country and location [20]
  • Pro: Deep customization with custom modules and workflow automation [19]
  • Con: Corporate card feeds and multi-level approvals require Standard plan [21]
  • Con: Deepest value requires the broader Zoho ecosystem (Books, People, CRM) [19]
  • Con: No corporate card offering; relies on connecting existing cards [20]
  • Con: Travel booking, per diem, and live budgets require Premium plan [21]

Zoho Expense offers unusually deep customization at a low price point—custom modules, workflow automation, webhooks, and configurable UI elements that most competitors don't expose. The active-user pricing model is genuinely cost-effective for companies where only a portion of employees submit expenses regularly.

The trade-off is that there's no corporate card offering—you'll need to connect your existing cards—and the platform delivers its deepest value when used alongside other Zoho products like Zoho Books and Zoho People. [19][20][21]

Commonly compared to: Expensify (for budget-friendly expense management), and SAP Concur (for global compliance and customization).

  • Best for: Small and midsize businesses that want an affordable, highly customizable expense management platform with strong global compliance features and active-user pricing. [19][20][21]
  • Highlights: Autoscan receipt capture with OCR, automated per diem calculations by country and location, corporate card reconciliation with real-time feeds, mileage tracking across multiple input methods, and active-user pricing starting at $4/user/month. [19][20][21]
  • Ideal if you need: A low-cost expense management tool with deep customization options and native integration with the broader Zoho ecosystem (Zoho Books, Zoho People, Zoho CRM). [19][20]
Pricing
Free (3 users); from $4/user/month
Integrations
Zoho Books, QuickBooks, Xero, Sage, Microsoft Dynamics, & Google Workspace.
Ideal Company Size
Small to mid-market