How to Migrate from BILL.com to Nexus AP: Step-by-Step Guide

Migrating from BILL.com to Nexus AP takes 1 to 3 weeks for most teams. The process involves exporting your data from BILL, connecting Nexus AP to your accounting system, running both platforms in parallel for two weeks, then cutting over completely.

If you have already decided to leave BILL.com, the migration itself is straightforward. This guide covers every step so your team can switch without missing a payment or losing historical data.

Why Teams Leave BILL.com

BILL.com has grown significantly since its IPO, but that growth has introduced friction for many AP teams. Common reasons teams migrate away include pricing increases that outpace the value delivered, per-user fees that limit who can access the system, customer support quality that has declined as the user base has expanded, and an interface that has become more complex without proportional improvements in core AP functionality.

According to Ardent Partners, 52% of organizations that switch AP platforms cite cost as the primary driver, followed by feature limitations at 31%.

Step 1: Export Your Data from BILL.com

Before starting anything in Nexus AP, secure a complete export of your BILL.com data. Log into BILL.com and export the following:

• Vendor list: Go to Vendors and export the full list as CSV. This includes vendor names, addresses, payment terms, and banking details.
• Open invoices: Export all invoices with status Unpaid or Scheduled. These are the invoices you will need to process in Nexus AP.
• Payment history: Export your full payment history for the last 12 to 24 months. This is your audit trail and you will want it for reference.
• Chart of accounts: Export your GL codes and department mappings if you configured them in BILL.
• Approval policies: Screenshot or document your approval routing rules. These will be recreated in Nexus AP.

Store all exports in a dedicated folder. You will reference these during setup and validation.

Step 2: Set Up Nexus AP

Setting up Nexus AP takes most teams 1 to 3 hours. The process follows a guided onboarding wizard.

Connect Your Accounting System

Nexus AP integrates natively with QuickBooks, Xero, NetSuite, and Sage. Connect your accounting system first because this imports your chart of accounts, vendor list, and open purchase orders automatically. Since BILL.com was syncing with the same accounting system, your vendor master data is already there.

Configure Matching Rules

Set your tolerance thresholds for invoice-to-PO matching. Most teams start with a 2% price tolerance and a 5% quantity tolerance, then adjust based on their first month of data. Nexus AP supports line-level 2-way and 3-way matching, which is a significant upgrade from header-level matching.

Set Up Approval Workflows

Recreate your approval routing rules. Nexus AP supports amount-based thresholds, department routing, GL code routing, and auto-approval for matched invoices under a configurable limit. Review the approval rules you documented from BILL and simplify where possible.

Invite Your Team

Add your AP team, approvers, and department managers. Nexus AP has no per-user fees, so add everyone who needs access without worrying about cost.

Step 3: Run Both Platforms in Parallel

This is the most important phase. Run BILL.com and Nexus AP simultaneously for two weeks.

During the parallel period:

• New invoices go into Nexus AP. Process them through capture, matching, and approval in the new system.
• Payments already scheduled in BILL.com continue to process there. Do not move in-flight payments.
• Compare results daily for the first week. Verify that Nexus AP captures invoice data accurately and routes approvals correctly.

The parallel period builds confidence. By the end of two weeks, your team will have processed enough invoices through Nexus AP to trust the system.

Step 4: Execute the Cutover

Once the parallel period is complete and your team is comfortable:

1. Confirm all BILL.com payments have cleared: No payments should be in Scheduled or Processing status.
2. Redirect your AP inbox: Update your AP email forwarding rules so incoming invoices go to your Nexus AP intake address.
3. Notify vendors: Send a brief communication to your top vendors informing them of the new submission process, if applicable.
4. Deactivate BILL.com integrations: Disconnect BILL from your accounting system to prevent sync conflicts.
5. Keep BILL.com read-only access: Maintain access for 90 days for historical reference and audit support.

What Timeline Should You Expect?

Simple environments (single entity, one accounting system, fewer than 500 invoices per month) typically finish in one week. Multi-entity setups with complex approval chains take closer to three weeks.

Common Migration Concerns

Will I lose my payment history?

No. Your payment history lives in your accounting system (QuickBooks, Xero, etc.), not just in BILL.com. The CSV export from BILL serves as a backup, and your accounting system retains the complete record.

Can I migrate mid-month?

Yes. Start the parallel period at the beginning of any week. The key rule is to let all BILL.com payments complete before fully cutting over. Most teams start the parallel period mid-month and cut over at the start of the following month.

What about vendor payment methods?

If you use BILL.com's payment network, you will set up payment methods in Nexus AP during onboarding. ACH and check payments are configured during the setup wizard. Vendors do not need to take any action on their end.

Start Your Migration

Sign up for Nexus AP and connect your accounting system to begin. The onboarding wizard guides you through every step, and most teams are processing invoices within hours of starting setup. If you are still comparing options, see our guide to the best BILL alternatives.