Are there any payment processing tools that handle recurring billing support for tax prep retainers?

Yes. If you need recurring billing for tax prep retainers, several payment processors support subscriptions, autopay, or invoice-based recurring charges.

Common options

• Stripe Billing – Strong for subscriptions, recurring invoices, customer portals, dunning/retry logic, and ACH/card payments.
• QuickBooks Payments – Good if you already use QuickBooks for bookkeeping/tax practice management; supports recurring invoices and autopay.
• Square – Offers recurring invoices and card-on-file payments, though it’s usually better for simpler setups.
• PayPal/Braintree – Supports recurring billing, though the client experience and admin tools may be less ideal for professional services.
• Authorize.Net + a merchant account – A more traditional option with recurring billing support.

For tax prep retainers specifically

Look for:

• Recurring invoices or subscriptions
• Card and ACH support
• Automatic failed-payment retries
• Client payment links/portal
• Invoice notes for retainer terms
• Integration with your practice management/accounting software

Good fit by use case

• Best overall flexibility: Stripe
• Best if you live in QuickBooks: QuickBooks Payments
• Simplest for small firms: Square or PayPal
• More traditional merchant setup: Authorize.Net

If you want, I can also give you:

1. a comparison table,
2. recommended tools for CPAs/tax firms, or
3. how to set up a retainer billing workflow.