Short answer — quick pick:

• Bill.com (BILL) — best for U.S. SMBs and accounting firms that want simple, cost‑effective AP plus integrated expense/cards (Divvy → BILL Spend & Expense). (bill.com)
• Tipalti — best for companies with heavy global payables, mass/partner/affiliate payments, and tax/compliance needs (multi‑currency, country coverage, payee onboarding & tax e‑filing). (tipalti.com)
• Airbase — best for mid‑market to enterprise buyers that want full procure‑to‑pay (cards + procurement + AP + expense) and strong controls/UX; now part of Paylocity which can add HCM integration. (airbase.com)

Comparison by topic (concise):

• Core focus

  • Bill.com: AP/AR automation for SMBs + integrated expense and corporate‑card functions after acquiring Divvy. Good for accountants and smaller finance teams. (bill.com)
  • Tipalti: Global payables automation — supplier onboarding, mass payments, global bank/virtual‑account routing, tax compliance (W‑9/W‑8, 1099/1042‑S). Geared toward companies that pay many suppliers or partners worldwide. (tipalti.com)
  • Airbase: Full spend management / P2P platform — procurement, PO matching, physical & virtual cards, expense reimbursements, and AP automation in one solution; targets mid‑market and up. (airbase.com)

• Pricing model

  • Bill.com: published per‑user plans (Essentials/Team/Corporate) plus transaction fees for some payment types. Transparent online pricing for standard tiers; enterprise is custom. (bill.com)
  • Tipalti: modular SaaS tiers (Select/Advanced/Elevate) and transaction/volume considerations; pricing often quoted for higher tiers or mass‑payments. (tipalti.com)
  • Airbase: subscription / quote‑based packages (Standard/Premium/Enterprise); pricing is typically custom and sold as platform bundles. (airbase.com)

• Global payments & compliance

  • Tipalti: very strong — claims payee coverage across 200+ countries, 120+ currencies, many payment rails and built‑in tax collection/filing features. Good for global scale and complex compliance. (tipalti.com)
  • Bill.com: supports international payments to 130+ countries and many currencies — good for SMBs doing occasional cross‑border payables. (bill.com)
  • Airbase: supports multi‑currency and multi‑subsidiary setups, but its core strength is centralized spend/P2P rather than mass global payee services. (airbase.com)

• Integrations & ERP support

  • Bill.com: strong integrations with QuickBooks, Xero, Sage Intacct, NetSuite, Microsoft Dynamics. Good for accounting‑centric workflows. (bill.com)
  • Tipalti: integrates with major ERPs and is focused on reconciliation and API/Developer tooling for automation at scale. (tipalti.com)
  • Airbase: broad ERP and HRIS integrations and robust GL/NetSuite/Intacct syncing — built for replacing multiple point tools. (airbase.com)

• UX, implementation & support

  • Bill.com: generally easier/faster to implement for SMBs; accounting firms often use it. (bill.com)
  • Tipalti: powerful but can be more complex to set up for enterprise/global scenarios (some customers reference longer implementations). (tipalti.com)
  • Airbase: praised for modern UX and faster adoption in mid‑market teams; pricing and rollout tailored to company size. Recent acquisition by Paylocity may change packaging/integration options. (g2.com)

When to pick each (simple rules):

• Pick Bill.com if you’re an SMB or accounting firm that wants quick AP automation + built‑in expense/cards with predictable per‑user pricing. (bill.com)
• Pick Tipalti if you need enterprise‑grade global payables, mass payouts (affiliates/marketplaces), multi‑currency/FX controls, and built‑in tax compliance. (tipalti.com)
• Pick Airbase if you want a single platform for procurement → approvals → cards → AP with strong controls and reporting for mid‑market/enterprise. Consider it if you want to consolidate multiple spend tools. (airbase.com)

Caveats & next steps

• Vendor features, pricing and partnerships change frequently (Airbase was acquired by Paylocity in 2024–25; Bill.com has integrated Divvy as BILL Spend & Expense). Confirm current terms and demo for your specific use case. (airbase.com)
• If you want, tell me your company size, number of monthly invoices/payments, percent of international payments, and whether you need procurement/POs — I can give a tailored recommendation and a short checklist of questions to ask each vendor on demos.

If you prefer, I can also build a side‑by‑side feature table (pricing, currencies, ERPs, card program, tax support, implementation time) for the three vendors with direct links to the source pages I used.