Vendor onboarding is the hidden AP bottleneck Vendor onboarding rarely shows up as a formal top priority for accounts payable (AP) teams. But in practice, it sets the pace for everything downstream: invoice processing speed, payment timeliness, vendor satisfaction, and even fraud exposure. For mid-market NetSuite teams processing 200+ invoices per month, vendor setup often stretches into weeks of back-and-forth across email, spreadsheets, PDFs, and disconnected forms.