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Accounts payable manager best practices for bill pay automation
If you’re an accounts payable (AP) manager at a growing company, your current process probably wasn’t designed from scratch. Invoices arrived, someone figured out how to handle them, and the workarounds became the process. At lower volumes, a shared inbox and a spreadsheet tracker can absorb the workload without breaking. At higher volumes, AP staff spend more time chasing approvals than processing invoices. As invoice counts keep rising, that informal process can create avoidable costs through late fees, duplicate payments, missed early-payment discounts, and a month-end close that slips because AP reconciliation isn’t finished.
Most accounts payable best practices guides tell AP managers to centralize intake, automate approvals, and track key performance indicators (KPIs). What many guides tend to skip is implementation order. This guide from Brex covers which step comes first, what to fix before automating, how to configure approval logic, and how to measure progress six months in. Sequence can be what separates an AP rollout that holds up from one that reproduces the same approval problems under new software. The diagnostic signals, practices, and KPIs below are ordered so an AP manager building or rebuilding an automated process can work through them start to finish.
5 signs your AP process needs bill pay automation
For many teams, the trigger for automation is a stack of operational signals showing the informal process has become the ceiling. Catching them early makes room for a planned improvement rather than a rushed cleanup. When several of these signs appear at once, the process often consumes time the team needs for close, vendor management, and exception handling.
1. Approvals consume more than a day of AP manager time per week
When follow-up takes longer than the invoice processing itself, the process can hit a structural ceiling. The time drain usually comes from pinging approvers, resending invoices buried in someone’s inbox, and chasing Slack messages that never got a response. If your week includes more approval follow-up than actual AP work, the routing and visibility layer could be broken. Working the team harder won’t close the gap.
2. Invoices are paid late because of process failures, not cash position
The money is in the account, but the invoice got lost, the approver was traveling, or no one was sure whose budget it hit. Late payment fees on vendor statements when cash is available point to a process problem rather than a liquidity one. At volume, that gap can also be a vendor relationship risk. Suppliers notice payment patterns, and late payments can affect pricing, terms, and priority during supply crunches.
3. Onboarding a new AP hire takes weeks before they can run a payment cycle solo
A repeatable process lives in documented steps, not in one person’s memory. When training time runs long because the outgoing AP staff member is the only one who knows how things work, the team has a single point of failure embedded in day-to-day operations. At 10 to 200 employees, a single resignation or extended leave can remove AP capacity entirely with no clear handoff plan.
4. Month-end close slips because AP reconciliation isn’t finished
When the AP team is still matching payments to invoices on the day the books should close, the controller ends up estimating accruals from incomplete data. That pushes close out by days and compresses the reporting window for leadership. A structured month-end close process depends on AP reconciliation finishing on time, and an informal AP process is often the last bottleneck standing between the team and a clean close.
5. Duplicate payment flags appear more than once a month
Occasional duplicates happen. Regular ones can point to a structural intake problem. The same invoice is entering through multiple channels with no single source of truth. At mid-market volumes, even a 1% to 2% duplicate rate translates to real overpayment exposure that finance has to claw back. When duplicates keep appearing after cleanup attempts, the root cause can be that the intake channel still isn’t centralized.
If several of these signals show up together, the informal process has likely reached its ceiling. The seven practices that follow address the root causes these signals expose.
7 AP manager best practices for bill pay and invoice automation
These seven practices are deliberately sequenced. Automation tends to encode whatever process it finds. If the process isn’t standardized first, automation can make existing problems move faster. The first three practices establish the foundation. The fourth and fifth introduce automation in an order many teams find easier to implement. The sixth addresses bill pay as a separate step, and the seventh covers the fraud-control dimension that many automation initiatives overlook until something goes wrong.
1. Create a single invoice intake channel
Before you change anything else, decide where invoices enter and enforce it. Optical character recognition (OCR), which converts invoice images into usable text, and AI capture only work on invoices that reach the AP platform. Every invoice that arrives in an employee’s personal inbox, a shared Slack channel, or a folder drive bypasses automation entirely. It doesn’t carry a capture timestamp, system record of receipt, or automatic routing. The automation can’t help with what it can’t see.
A dedicated AP email address, vendor portal, or inbox that feeds directly into the AP platform is a common way companies create a single point of entry for invoices. Many pair this with a communicated cutoff date, after which invoices submitted through other channels are no longer processed. This kind of single-intake structure tends to reduce downstream issues.
An invoice that enters outside the process is harder to reconstruct if an auditor requests documentation. It can also create a duplicate when someone eventually forwards it into the official channel weeks later. For that reason, many finance teams treat single-intake discipline as the foundation on which the rest of the AP process builds.
2. Clean the vendor master before configuring any automation
Automation depends on invoices cleanly matching vendor records. If your vendor management records have duplicates, inconsistent naming (for example, ACME LLC vs. Acme vs. Acme, Inc.), or outdated banking details, you could end up automating a mess. Run a deduplication pass, and implement dual-control verification for any changes to bank details or remittance addresses before you configure anything else.
According to the AFP Payments Fraud and Control Survey, 76% of organizations reported attempted or actual payment fraud last year. The same AFP data show that 74% of organizations faced attempted or actual business email compromise or fraudulent emails, the highest source of fraud by almost 20 percentage points. A clean vendor master with controlled change processes provides the AP team with a more reliable foundation for payment accuracy and control of vendor records.
3. Document GL coding rules and the approval-threshold matrix
Invoice automation can suggest general ledger (GL) codes based on prior coding patterns, but only if those patterns are consistent enough to learn from. Before you switch anything on, write down the coding logic your team already uses. Document which vendors map to which GL accounts, how split coding works across cost centers, and the rules for department allocation. This becomes both the instruction set for the automation and the onboarding document for the next AP hire.
The approval-threshold matrix should be documented alongside coding rules, using three tiers as a starting point. Routine invoices are auto-approved after AP review, midrange amounts are routed to the department head or budget owner, and high-value invoices require controller or chief financial officer (CFO) sign-off before payment release. Without documented rules, the AP platform has fewer instructions to encode, and the AP manager tends to become the default approver for much of the queue. That recreates the approval-chasing problem under new software.
4. Design approval routing for a lean AP team
Once the threshold matrix is documented, configure the approval workflow to enforce it and build in the controls that keep a small team honest. For a two-person AP function, separation of duties typically means one person enters and codes invoices, while another approves and releases payments. That split provides an independent check on errors and keeps control over payment release from sitting with a single person. Most AP platforms support this through role-based permissions you set before go-live.
Two workflow design decisions can help prevent common approval failures. Set service-level agreements (SLAs) for each tier, with routine approvals and high-value invoices assigned response windows that fit the team’s operating cadence. Then configure automatic escalation with a reminder and a notification to the approver’s manager when the window expires. Require approvals within the AP platform or in a workflow that preserves the approval record. Approvals made in Slack, by email reply, or verbally confirmed in a meeting may not appear in the audit trail, depending on the platform and workflow design. Internal controls for accounting rely on documented approval records.
5. Automate invoice capture and straight-through processing for routine invoices first
Start automation where the outcome is most predictable. Use OCR and AI invoice capture across incoming invoices, then configure straight-through processing only for the subset that meets all three conditions at once. The vendor is established in the master, the amount falls within the auto-approve threshold, and there’s no coding exception. Software-as-a-service (SaaS) subscriptions, utilities, and recurring vendor payments that consistently match the vendor record can be a good starting point. Everything else goes through a human review step until you’ve mapped the exception patterns and tightened the rules.
Starting here can give the team a first use case for AP automation before expanding it to more complex transactions. For invoices backed by purchase orders, configure invoice-matching rules with defined tolerance bands, including two-way matching where appropriate. Define matching tolerances explicitly before go-live. Without them, a minor price variance can trigger an exception that defeats the automation. Exception overload is one of the fastest ways to turn a promising rollout into a manual cleanup project, which is why the routine invoice bucket can be the best starting point.
6. Implement bill pay automation as its own step
Invoice automation gets an approved liability on the books. Bill pay automation is what turns that approved liability into a cleared payment. OCR capture, GL coding, PO matching, and approval routing handle the front end. Payment scheduling, payment execution, and syncing payment status back to the GL handle the back end. A tool that automates one but not the other leaves a manual gap in the middle, which is where most of the last-mile AP work still lives for teams that haven’t connected both phases.
When configuring bill pay automation, document the preferred payment method per vendor category. Route domestic recurring vendors to ACH, international vendors to wire, and any remaining vendors that will not accept ACH to check. Use virtual cards when the vendor accepts them and the rebate is worth capturing. Configure these preferences in the payment platform so the AP team doesn’t have to make a payment-method decision on every run.
A well-configured bill pay tool can pull approved invoices, schedule them according to due dates and cash flow rules, and automate vendor payments with less manual handling. Connecting both phases automates accounting processes end to end and can help make the last mile of AP more reliable.
7. Treat vendor onboarding as a fraud control, not a clerical task
Vendor onboarding can be one of the highest-level control points in the AP workflow, although many teams tend to treat it as admin work. A weak vendor record can let an improper invoice pass through automated checks undetected, which means onboarding controls matter before payment automation begins. Teams with the strongest payment accuracy tend to treat vendor setup as a control activity that shapes fraud exposure, documentation quality, and payment accuracy from day one.
A common control-oriented approach to vendor onboarding uses four steps:
- Collect the W-9 before the first payment.
- Run taxpayer identification number (TIN) matching, which checks vendor tax ID information against the IRS database, and log the result.
- Require dual-control verification for bank-detail changes, in which a second person independently confirms the account details with the vendor via a contact established before the request arrived.
- Log each change to a vendor record with a timestamp and a user ID.
The Association of Certified Fraud Examiners (ACFE) 2024 Report to the Nations analyzed 1,921 cases of occupational fraud across 138 countries. It found that 21% of all occupational fraud cases occurred at organizations with fewer than 100 employees, with a median loss of $141,000 per case. Discipline at vendor setup can give the AP team cleaner records when exceptions or audit questions surface later, and it prevents payment risk from entering the workflow in the first place.
Five AP KPIs to track through automation rollout
KPIs without baselines are decoration. Measure the current state before implementing the practices above, then set targets against your own numbers, not against top-20% benchmarks, as those figures represent larger organizations with multi-year automation programs. Aim for directional improvements, including a meaningful reduction in cost per invoice, a shorter cycle time, and a lower exception rate. The Ardent Partners State of ePayables 2025 report, which surveyed 204 AP professionals, provides industry benchmarks worth checking against your own numbers.
1. Cost per invoice. Total AP operating cost divided by the number of invoices processed. Check the latest Ardent Partners report for current industry and top-tier benchmarks, then set a Year-1 target based on your own baseline rather than a benchmark built for larger, more mature AP functions.
2. Invoice processing cycle time. Days elapsed from invoice receipt to payment. A Year-1 target of four to five days may be a reasonable directional benchmark, especially when approval workflow automation is one of the earliest capabilities deployed.
3. Exception rate. The percentage of invoices that require manual intervention before they can be processed. The latest Ardent Partners figures for the current industry average can give a benchmark, then set your own target based on where you’re starting from. Getting exceptions down in Year 1 often depends on fixing vendor submission guidelines and coding rules before adjusting automation configuration. If the exception rate rises after automation launches, investigate whether the vendor master, coding rules, or intake channel has changed.
4. Touchless processing rate. The percentage of invoices processed end to end without human touch. Set a Year-1 target that’s realistic for a new implementation rather than one built for best-in-class programs with years of tuning behind them.
5. On-time payment rate. The share of invoices paid by their due date, tracked separately from the early-payment discount capture rate. On-time payment rate reflects process reliability, while discount capture reflects cash management optimization. Tracking accounts payable metrics in tandem gives the finance leader a more complete picture.
Exception rate and touchless processing rate are operational metrics the AP manager should review weekly. Cost per invoice, cycle time, on-time payment rate, and early-payment-discount capture are monthly metrics reviewed at close and visible to the controller. Each metric should have a trigger threshold that defines when an investigation is required. A metric without one ends up becoming a number on a dashboard nobody acts on.
5 AP automation mistakes that slow everything down
These five mistakes appear across companies of different sizes, but they hit 10 to 200-person AP management teams hardest because lean teams have less margin to absorb the costs of the recovery effort.
Buying enterprise-scale software before the process is ready
Platforms designed for 500-invoice-a-month operations bring configuration complexity that a 50-invoice-a-month team can’t maintain. The overhead of managing a tool built for a different scale can slow the team down and may result in a partial implementation that no one fully adopts. Start with a tool that matches current volume and bandwidth, then scale up capabilities as the process matures.
Automating intake before cleaning the vendor master
Vendor master cleanup should be a prerequisite instead of a parallel workstream. Automating intake first means the new platform inherits the same duplicate records, inconsistent naming, and outdated banking details from the old system. The automation moves faster, but the underlying data quality problems remain and create exceptions at scale.
Configuring too many approval tiers at launch
Too many approval tiers can create routing confusion and slow approvals, resulting in performance below what the manual process achieved. Start with three tiers (auto-approve, department head, controller/CFO) and add complexity only when a documented gap in the current structure appears. Keep the approval logic aligned to how the business currently makes spending decisions rather than how someone imagines it might need to be in the future.
Treating the exception rate as a vanity metric
A high exception rate after launch points to specific, addressable root causes in the vendor master, coding rules, or intake channel. Review exception categories weekly and assign named owners to each category. When exceptions and rework persist after automation is in place, the root cause is almost always data quality and organizational readiness rather than the automation tool itself.
Failing to train approvers before going live
If approvers don’t know their SLA, what escalation looks like, or why they can no longer approve via Slack reply, the automation runs, but approvals stall. A one-page SLA document and a 15-minute walkthrough before launch can prevent most of this.
This story was produced by Brex and reviewed and distributed by Stacker.
