ChargeOver - ChargeOver automates recurring billing, subscription billing, & payment acceptance. A SaaS that integrates with Xero, Quickbooks, & has an API. Free trial.

Bill.com - Bill.com provides ACH payments processing, automates your accounts payable and accounts receivable processes.

fusebill - Fusebill is the leading recurring billing and subscription management software for businesses. Try Fusebill for subscription billing made easy!

Sage Intacct - Intacct is a cloud-based accounting and financial management system that is designed for the businesses of all levels.

MinuteDock - Web-based time tracking software designed to integrate with the Xero accounting package.

Tipalti - Tipalti is a supplier payments automation solution to streamline all phases of the AP and payment management workflow.