Glad you're in. This page is your guide for the next two weeks in the Harriet beta. Have a quick read before you get started.
Sign in to the app: assistant.harriet.tax
Create an account there, then you're ready to go.
Please don't file with this yet
Harriet is in a closed beta. The output is not tax-advisor verified yet, and we want to test the results together with you first. So please don't use Harriet's numbers for your real tax filing yet. During this phase, please don't submit anything to the Finanzamt or via FinanzOnline based on Harriet.
What we'd love you to do: walk through the full flow once with your real receipts and bank data from January 2026 until today, as a dry run. That way we can see where Harriet already helps and where she's not there yet.
If you'd like a quick chat with Mario before you start, you can book a 15-minute slot. It's not required, you can also just click through it on your own.
Step 1: Go through the in-app onboarding
Sign in at assistant.harriet.tax. The first time you log into Harriet, there's a short onboarding flow: a few questions about you, the kind of work you do, your rough numbers, and your tax-advisor setup (do you have one, would you keep one, would you also be open to filing on your own).
Please take a few minutes for these questions. This is genuinely important to us: we want to understand how our first testers currently handle their taxes, what their setup looks like today, and where Harriet should fit in.
Step 2: Upload receipts and bank data
Collect everything from 1 January 2026 until today:
- Incoming invoices (everything you paid, e.g. software, hardware, coworking, travel, training, office supplies)
- Outgoing invoices (everything you billed)
- Bank statement as CSV for the same period (one file per account is enough)
Upload everything into Harriet. If you're unsure whether a receipt belongs in there, upload it anyway. We want to see how Harriet handles it.
Step 3: Review the classification
Harriet automatically sorts your receipts into tax categories. Go through the list once and:
- Mark personal expenses as private
- Fix any wrong categories
- Let us know in the app when something is sorted incorrectly, an expense is missing, or you're unsure whether something is deductible. That's what helps us most.
Step 4: Look at the UVA number (dry run)
Have Harriet calculate the Umsatzsteuer-Voranmeldung for your period and have a look at the number. If you can, compare it to what you or your tax advisor would have calculated.
Please don't submit this number. It's a dry run for us, so we can see how close Harriet already gets.
Step 5: 20-minute debrief with Mario
Once you're through, book a debrief slot via the same link. We'll walk through what worked for you, what didn't, and how far Harriet's number is from your real one.
If something breaks: WhatsApp community
We have a small WhatsApp community for the beta, with separate groups for bugs & feedback and for announcements. Feel free to join. You can report issues, ask questions, or just follow what the others are running into.
If something is urgent or you'd rather talk for a minute, Mario shared his number with you, or you can grab a quick slot via the link above. No question is too small.
Time frame
We learn fastest when feedback comes back quickly. If you can make it through the flow and do a debrief with Mario by 21 May 2026, that would be amazing. If you need a bit more time, just let us know.
Important notes
- Don't file with this. Harriet's output is not tax-advisor verified at this stage. Please don't use the numbers for your real tax filing.
- Keep backups of your receipts. We're in beta. In rare cases, data may be lost.
- The Beta Terms apply.