We use Quickbooks Online for accounting, so utilize its built-in invoicing. It automatically emails tenants monthly, they click a link, enter their account details and submit. It also suppose automatic payments, where we collect the Tenants information once, and it takes payment from their account each month automatically, sending an email receipt. For all payments, we accept payments from a checking or savings account only, and it's no charge. Quickbooks Online charges for card transactions like most, so we do not accept those.