Validating an Idea: invoicing with built in installment plan scheduling

Hello!
If you are freelancing or running a small business, you've probably sent someone an invoice, and you've probably had a client be slow to pay you. Getting people to cough up the cash is a high touch interaction but addressing debt in your accounts receivables can take you away from bringing in new revenue.

Enter potential offering.

• High touch drip campaigns styled by us to match invoicer brand.
• Invoicee facing web app to process payments, set up an install plan and payment schedule for large amounts

Just spit balling at this point. Invoicing software is very commoditized, but I'm hoping the ability for an invoicee to setup an installment plan and a payment schedule that works for them differentiates the offering, and allows for company's to better manage their cashflows.

What issues do you run into operating the back-office of your small business?

Cheers,
Doug