Invoices to clients
A freelancer or a small team does not need an accounting suite to send a client an invoice for work done. In killBottleneck the AI assistant does it: you say to whom and for what, it prepares the invoice for approval, and after you confirm you get a PDF with a QR payment code.
The essentials
- The assistant issues the invoice ("Issue an invoice to Karel for 2 hours of consulting at 800 CZK"). You always see a card with the items and totals first and confirm it.
- Amounts, VAT and the invoice number are computed by the app, not by the language model. The number series runs per year without gaps (e.g.
20260001,20260002): shared by the organization, or a user's own when they have their own supplier details (see below). An administrator sees everyone's invoices, including colleagues' invoices with their own details (and therefore the account number printed on them). - You download and keep the PDF. killBottleneck is not the legal archive of tax documents (keeping them for the statutory period is on you) — the app keeps the invoice data, and the PDF can be generated again identically at any time.
What to prepare
- Supplier details (yours) — name or company, address, company ID (IČO), VAT ID (DIČ), whether you are a VAT payer and the rate, bank account (a Czech account number; the app derives the IBAN for the QR payment), e-mail, optionally a number prefix (
FV→FV20260001) and the default due period. There are two kinds:- Shared by the organization: the administrator fills them in under Organization settings → Issuing invoices. Anyone on the team issues invoices with them, in one shared number series.
- Your own: every user can set theirs under My account → My invoice details. They take precedence over the shared ones and that user's invoices get their own number series (three freelancers in one instance each invoicing for themselves). "Remove mine" switches back to the shared details. If the applicable details are missing and you ask for the first invoice, the assistant shows a form (an administrator first chooses "whole organization" or "only me") and saves the answers (after confirmation). You can also tell the assistant "change my invoice details" or "change the organization's details".
- The client in the address book: clients are the same address book you know from time tracking and project assignment (Tasks → Clients). For invoicing add the address, company ID, VAT ID and e-mail — either in the clients dialog (expand Billing details) or tell the assistant: "Create the client Karel Novák, company ID 12345678, Krátká 3, Brno."
A client from a business-card photo
Take a photo of the card and send it to the assistant with "save the contact from the business card". The assistant takes the name, address and IDs from the transcript and shows a card with what will be saved — check the company ID and ZIP in particular, a photo transcript is not infallible. The photo is not stored; only the transcript remains (as with other photos in the assistant).
Issuing an invoice
Tell the assistant to whom and for what:
- "Issue an invoice to Karel for 2 h of consulting at 800." — if several Karels exist, the assistant asks which one.
- "Invoice Novák: logo design 6,500 CZK and 3 hours of consulting at 900, due in 10 days."
The card shows every item (description · quantity × price = amount), for VAT payers the net amount, VAT and total, and the due date. After confirmation the app assigns the number and the card offers Download PDF and Open in Documents.
An issued invoice is immutable — it carries a copy of the supplier and client details from that moment. A later change of the client's address does not change it. If an invoice is wrong, issue a new one.
Where to find invoices
In the assistant open Documents and pick the Invoices filter (you get there also from My account → My invoice details → Issued invoices in Documents). The list shows the number, customer, amount and paid/unpaid; you see your own invoices, an administrator all of them. At the top there is a filter by month issued and Download all (ZIP), which downloads the PDFs of all listed invoices in one file (faktury-2026-10.zip) — for your accountant. The detail has Download PDF and a Paid toggle. Otherwise an invoice is immutable; corrections are made with a new invoice. "Download all my data" in My account is the app data export (JSON); invoices are not in it.
What is on the PDF
Invoice number, supplier and customer (address, company ID, VAT ID), dates of issue and due (for VAT payers also the date of taxable supply), the items table, totals, a note, the payment block with the account number, IBAN and variable symbol, and a QR payment code in the format Czech banking apps read. A non-VAT payer has "Not a VAT payer" printed. The organization logo (if set) is printed in the header.
Limits of the first version
- Currency CZK only; a VAT payer has one rate per invoice (default from the profile, can be changed per invoice). Advance invoices, credit notes, reverse charge and foreign currencies are not supported yet.
- The PDF is created in your browser and not stored — the app keeps only the invoice data.
- At most 50 items per invoice and 500 invoices per instance.
Privacy
The client address book and issued invoices are content of your instance like maps and documents: with self-hosted killBottleneck they stay with you; in the hosted edition we process them under the data processing agreement. AI processing (issuing through the assistant, the business-card transcript) goes through providers that neither keep the data nor train on it — see AI assistant.