BillingEngine VS Mind Diary

BillingEngine's answer

BillingEngine is built around e-invoicing from the start. Every invoice is created as an e-invoice (ZUGFeRD and XRechnung, EN 16931), and every plan, including the free one, includes your own inbox for incoming e-invoices without a volume limit. Your tax advisor gets read-only access and can collect the DATEV data set themselves. Beyond the app, BillingEngine offers free tools that need no account (e-invoice validator, viewer, generator and Leitweg-ID checker), a documented REST API and an MCP server for AI assistants. Invoices can be written in six languages and 32 currencies, and all documents are archived in a GoBD-compliant way.

Mind Diary's answer:

MindDiary connects what happens before, during, and between therapy sessions in one workspace. Alongside practice management features such as digital intake, appointments, telehealth, invoicing, and therapist-reviewed AI notes, MindDiary helps therapists maintain continuity between sessions through client journaling, check-ins, homework, and session preparation. Instead of treating each appointment as an isolated event, MindDiary brings relevant client context together over time so therapists can prepare for sessions with a clearer picture of progress, concerns, and between-session activity. AI-assisted features support the therapist rather than replacing professional judgement.

BillingEngine's answer

It is a focused, affordable tool for people who mainly need correct invoices. You get compliant e-invoices and an inbox for incoming ones on a permanently free plan, and the paid plans start at EUR 7.50 per month. There is no lock-in: all data can be exported at any time as DATEV, CSV, XLS, XML or PDF. If you want the full range of a large accounting suite, a bigger competitor may fit better. If you want simple invoicing that is ready for the e-invoicing mandate, BillingEngine is a good choice.

Mind Diary's answer:

MindDiary is designed specifically around therapy workflows rather than being a generic scheduling or medical practice-management system. It combines digital intake, client management, session preparation, therapist-reviewed AI note drafting, telehealth, appointments, invoicing, revenue follow-up, journaling, homework, and between-session check-ins in one platform. A key difference is MindDiary's focus on between-session engagement and longitudinal client context. Therapists can use permissioned journal entries, check-ins, homework, recent sessions, and other relevant information to prepare for upcoming appointments instead of piecing context together across multiple disconnected tools.

BillingEngine's answer

Freelancers, sole traders and small businesses in Germany, including small-business owners (Kleinunternehmer) and tradespeople, who write a moderate number of invoices and want them to be compliant without learning about XML formats. A second group is tax advisors, who work with their clients' data, and developers who connect invoicing to their own tools through the API.

Mind Diary's answer:

MindDiary is built for counsellors, psychotherapists, therapists, psychologists, group practices, and therapy clinics. It is particularly suited to practitioners who want to reduce administrative work while improving continuity of care through digital intake, session preparation, clinical documentation support, client journaling, homework, check-ins, appointments, telehealth, and practice-management tools. MindDiary currently has a particular focus on therapy practices in Ireland and the United Kingdom, while the platform is designed to support therapists internationally.

BillingEngine's answer

BillingEngine was founded to offer small businesses a simple invoicing solution, something its founders could not find on the German market at the time. It launched in 2014 and has been developed continuously with its users and a small team. Since e-invoicing became mandatory for receiving invoices in Germany in 2025, e-invoices have moved to the center of the product. Today more than 2,500 active users rely on it. BillingEngine is developed by DesignBits in Hamburg.

Mind Diary's answer:

MindDiary was created around a simple observation: therapy software typically concentrates on what happens inside the appointment, while much of the useful context develops between sessions. Therapists often have intake information, notes, journals, homework, appointments, invoices, and client communications spread across different systems. MindDiary was built to bring these workflows together and make relevant longitudinal client context easier to use when preparing for the next session. The goal is not to automate therapy or replace clinical judgement. It is to give therapists a better workspace for understanding context, reducing administration, maintaining continuity between sessions, and running their practice.

Mind Diary's answer:

MindDiary does not currently publicly disclose individual customer or practice names.

Mind Diary's answer:

MindDiary is a modern cloud-based web application built primarily with React and TypeScript on the frontend and .NET/C# services on the backend. Its infrastructure uses technologies including AWS, Cloudflare, PostgreSQL, Stripe, and modern AI/LLM services. The platform is designed with security, privacy, scalability, and therapist control over AI-assisted workflows in mind.