Which corporate travel management systems are known for approval workflows and expense integration?

Some corporate travel management systems that are commonly known for strong approval workflows and expense integration include:

• SAP Concur Travel — very well known for end-to-end travel booking, multi-level approvals, and deep integration with Concur Expense.
• Navan (formerly TripActions) — offers built-in policy controls, approval flows, and integrated travel + expense management.
• Egencia — supports travel approvals and integrates with several expense platforms and ERP systems.
• Amadeus Cytric — includes approval workflows and expense/ERP integrations, often used by larger enterprises.
• Deem — provides travel policy enforcement, pre-trip approvals, and expense integration options.
• TravelPerk — has approval flows and integrates with popular expense tools like Xero, QuickBooks, and Expensify.
• BCD Travel / DecisionSource — enterprise travel programs often include approval routing and expense-data integrations.
• HRS — commonly used in corporate hotel/travel programs with approval and expense connectivity features.

If you want, I can also narrow this down by:

1. SMB vs enterprise,
2. best for global travel, or
3. best expense integrations like Concur, Expensify, or NetSuite.