Zyloft Desk documentation

• Windows 10 (version 1809 or later) or Windows 11, 64-bit.
• No administrator rights and no extra software needed: the installer brings everything along.
• An internet connection for activation and the regular license check. Day-to-day work runs offline.
• Zyloft Desk is a single-user program. There is no Mac or Linux version and no cloud sync.

Zyloft Desk is sold through Polar, our reseller. After paying, you get a receipt by e-mail with a link to Polar's customer portal. There you find:

• The installer to download.
• Your license key (lifetime license). It unlocks the program and never expires.
• A maintenance key for updates. Maintenance runs for one year; the first year is included with a new license. After that you can renew it with the yearly update package (see License and maintenance).

Keep the receipt e-mail: you need the keys again when you move to a new PC.

1. Download the installer from Polar's customer portal.
2. Double-click it. Zyloft Desk installs for your Windows user and adds shortcuts to the Start menu and the desktop. No administrator rights are needed.
3. Zyloft Desk starts automatically when the installation is finished.

The program is installed separately from your data. Uninstalling it (Windows Settings → Apps) never deletes your clients, invoices or backups.

1. At the first start, the window Activate Zyloft Desk opens.
2. Paste your license key (not the maintenance key) and click Activate. Your PC needs to be online for this.
3. Then open Settings → License, enter your maintenance key under Maintenance (updates) and click Activate maintenance key.

A license can be active on a limited number of PCs. Before you move to another computer, free the seat with Settings → License → Deactivate on this PC.

Before you can issue an invoice, Zyloft Desk needs the details that German law (§ 14 UStG) requires on every invoice. Open Settings and fill in:

1. Business: your full name (owner), optional company name, street and number, postcode, city, country, e-mail and phone.
2. Tax and bank details: tax number and/or VAT ID, IBAN and BIC, how you account for VAT (cash or accrual accounting, see Reports), whether you file the VAT return monthly or quarterly, and whether you are a small business under § 19 UStG.
3. Number ranges and defaults: invoice and quote prefix, the next number, payment terms in days, your default hourly rate and your logo (PNG or JPG, printed at the top of quotes and invoices).
4. Folder: a backup folder, ideally on another drive or in a synced cloud folder, and the archive folder for invoice PDFs.

Click Save (or press Ctrl + S). Then create your first client under Clients and you are ready to go.

• Switch the program language with DE | EN in the title bar. The window is rebuilt on the same page without restarting; unsaved changes are confirmed first.
• Each client has its own Language for quotes and invoices, independent of the program language. You can change it per document while it is a draft.
• Settings → Appearance → Theme: Same as Windows, Light or Dark.

Your dashboard: open and overdue invoices, revenue this month and this year, unbilled hours (one click turns them into a draft invoice) and the VAT payable for the current filing period. As a small business it also shows how close you are to the § 19 UStG turnover limits.

Create clients with New client (Ctrl + N). The Client type decides how VAT is applied on quotes and invoices:

The country is entered as an ISO code (DE, AT, NL, US …). For public authorities, enter the Leitweg-ID / buyer reference (XRechnung). Clients that already have quotes or invoices cannot be deleted, only archived; Show archived brings them back.

Every project belongs to a client and is billed in one of two ways:

• Fixed price: the budget is the agreed price.
• Time & material: billable hours × hourly rate, with an optional budget as a cap.

The project view compares budget and actual (recorded hours × rate), and shows revenue, expenses, margin and your effective hourly rate. Add Milestones such as “30 % deposit” and bill them with Invoice selected milestone, or bill all open hours with Invoice unbilled time.

Statuses: Lead, Active, On hold and Completed. A project that has invoices cannot be deleted; set it to Completed instead.

One entry bar covers both ways of recording time:

1. Pick the project (the last one you used is preselected).
2. Describe the work under What did you work on?. The text appears on the invoice.
3. Either type a duration and press Add (or Enter), or click Start timer and later Stop and record.

Durations can be written as 1:30, 1,5, 90m or 1h30, or picked from the quick choices (0:15 to 4:00). The timer keeps running when you close and reopen the program. Entries are grouped by day with daily and weekly totals; edit or delete them with the buttons on each row. Invoiced time can no longer be changed.

Record business expenses with vendor, date, category and amount. Entering the gross amount calculates net and input VAT (19 %, 7 % or 0 %). Attach a receipt (PDF, PNG or JPG, up to 25 MB): Zyloft Desk stores a copy in its data folder, so the original can be moved or deleted. Assigning a project includes the expense in that project's margin.

Categories include Office & supplies, Software & licences, Hosting & domains, Phone & internet, Travel, Training & literature, Advertising & marketing, Insurance, Subcontractors, Bank fees and Other.

Quotes are numbered automatically (by default AN-2026-0001) and go through the statuses Draft, Sent, Accepted and Rejected. Add items, preview and save them as PDF. Once a client accepts, Convert to invoice creates a draft invoice with the same items.

Create invoices with New invoice, from a project (unbilled time or a milestone) or from an accepted quote. An invoice moves through these steps:

1. Draft: freely editable. Set the client, invoice date, service period, due date and items. The VAT treatment comes from the client type.
2. Issue: Issue … checks the mandatory contents (§ 14 UStG), assigns the next gap-free number (by default RE-2026-0001, restarting each year) and archives the PDF read-only in your archive folder. From then on the invoice can no longer be changed (GoBD).
3. Paid: Mark as paid with the payment date. With cash accounting, the payment date decides which VAT period the sale belongs to.

Corrections are only possible with Cancel invoice …: Zyloft Desk issues a numbered cancellation invoice (Stornorechnung) with negative amounts that references the original, and the invoiced time and milestones become billable again. Copy as new draft then gives you a corrected starting point. Drafts that were never issued can simply be deleted.

Every issued invoice is archived as a ZUGFeRD 2.3 / Factur-X PDF: readable by people and importable by accounting software. For an issued invoice you can also export:

• Export ZUGFeRD PDF (Factur-X): to send by e-mail to business clients.
• Export XRechnung (XML): for public-sector clients. XRechnung also needs your e-mail and phone (Settings), the client's e-mail and, for authorities, the Leitweg-ID. Zyloft Desk lists anything missing before exporting.

Since 2025, businesses in Germany must be able to receive e-invoices; issuing them becomes mandatory step by step until 2028. Ask your tax advisor which date applies to you.

Turn on Small business under § 19 UStG (Kleinunternehmer, no VAT) in Settings → Tax and bank details. Quotes and invoices to clients in Germany and to private clients in the EU then carry no VAT and the note “Gemäß § 19 UStG wird keine Umsatzsteuer berechnet.” Business clients in the EU (reverse charge) and clients outside the EU are treated as before, because the place of supply is abroad.

The overview shows your revenue against the limits (previous year € 25,000, current year € 100,000) and warns from 80 %. Issued invoices are never changed when you switch the setting.

• VAT return (USt-Voranmeldung) per month or quarter, with the form fields Kz. 81, 21, 45 and 66.
• EC Sales List (Zusammenfassende Meldung) per quarter for reverse-charge supplies.
• Revenue by client and by project.
• Export as CSV for every table, plus all invoices or expenses of a year (semicolon, decimal comma, UTF-8: opens directly in Excel).

With cash accounting (Ist-Versteuerung, the default), 19 % sales count by payment date; with accrual accounting (Soll-Versteuerung) by invoice date. Reverse-charge and non-taxable supplies count by the end of the service period, input VAT by the payment date of the expense.

On the Tax advisor page, choose a month, a quarter or the whole fiscal year, then:

• Documents as ZIP …: sales invoice journal and expense list (CSV), the archived invoice PDFs, all receipts and, if set up, the DATEV file, plus a short read-me.
• DATEV file only …: a DATEV booking batch (EXTF format) that imports into DATEV and most German accounting tools.

For the DATEV file, enter the consultant and client number from your tax advisor under DATEV settings, choose SKR 03 or SKR 04, the account length and the start of your fiscal year. The suggested accounts should be confirmed once by your tax advisor; import a first file as a test. Export each fiscal year separately.

If your work gives you access to a client's personal data, you need a data processing agreement under Art. 28 GDPR (AV-Vertrag). The Data processing agreement page creates one as PDF, always in German: the parties come from the client and your business settings, Annex 1 describes the project, Annex 2 your technical and organisational measures and Annex 3 your sub-processors. Save as default keeps your terms for the next agreement.

Estimate a project before quoting: effort in hours × hourly rate with a risk buffer, fixed-price packages, discount, your own costs and the resulting margin. Use as quote turns the result into a quote.

Zyloft Desk backs up automatically: at startup and every hour while it is open if the last backup is older than 24 hours, and when you close it. The last 30 backups are kept. Back up now creates one at any time.

To restore, select a backup and click Restore selected …, or use Restore from file …. The current state is saved first, then Zyloft Desk restarts with the restored data.

If your backup folder is in the cloud, turn on Encrypt backups under Settings → Backup and choose a backup password (at least 8 characters). Backups are then saved with AES-256 encryption, and existing backups in the folder are converted too, so no readable copy stays in the cloud.

On your own PC, backups and restores run without asking for the password. On a new PC, Restore from file … asks for it.

Settings → App lock sets a password (at least 8 characters) that Zyloft Desk asks for at every start. Lock now locks the running program. After wrong attempts you have to wait a little longer each time.

The lock protects access through the program; the database file itself is not encrypted. For full protection, use Windows BitLocker. There is no password recovery: restoring a backup made before the lock was enabled removes it.

Without active maintenance, your version keeps working exactly as it is; you only stop getting updates. To renew, buy the update package (Settings → License → Buy or renew maintenance) and enter the new maintenance key under Enter maintenance key. It replaces the old one.

The license is confirmed online in the background at every start. Without internet, Zyloft Desk keeps working for up to 7 days; after that it needs to go online once before it starts again. Check online now confirms it on demand.

Moving to a new PC: on the old PC click Deactivate on this PC (this frees both keys), make a final backup and copy it together with the archive and receipts folders. On the new PC, install Zyloft Desk, activate it, then use Restore from file … and copy the folders back (see Where your data lives).

With active maintenance, Zyloft Desk checks for updates about 30 seconds after starting and then once a day. When a new version is available it asks New update available:

• Yes, update downloads the update, installs it and restarts. Your data is kept and adapted automatically (with a backup first).
• No changes nothing; you will be asked again at the next start.

Zyloft Desk never restarts without your permission. To check right away, use Settings → About Zyloft Desk → Check for updates.

All data is stored on your PC in %LOCALAPPDATA%\ZyloftDeskPro (paste this into the Explorer address bar, or use Settings → About Zyloft Desk → Data folder):

Nothing is sent to us or to third parties, apart from the license check and the update check.