The Inkvoice blog
Invoicing tips, freelancer playbooks, and self-hosting guides from the team building Inkvoice.
How to Send an E-Invoice (XRechnung or ZUGFeRD) With Inkvoice
A step-by-step guide: turn on E-Rechnung, set up your details, VAT rates and customers, create the e-invoice and send it by email. With screenshots, and a way to check the file yourself.
Read →Germany's E-Invoicing Mandate: Deadlines and Who Is Exempt (2025 to 2028)
Since 2025 every business in Germany must accept e-invoices, and sending them becomes mandatory in 2027 and 2028. The deadlines, the €800,000 rule and the exemptions, with the exact paragraphs.
Read →XRechnung vs ZUGFeRD: The Difference, Shown With Real Files and Validator Results
Both German e-invoice formats meet EN 16931, but they look and behave differently. The same invoice in both formats, what the official KoSIT validator checks, and the XRechnung rules our own first version failed.
Read →Inkvoice Is Now on iPhone and Android
The free Inkvoice app for iPhone and Android is on the App Store and Google Play. Create invoices, record payments and log expenses from your phone, connected to Inkvoice Cloud or your own self-hosted server.
Read →FreshBooks Alternative: Free & Open-Source Options for 2026
Looking for a FreshBooks alternative? Why freelancers switch, what to look for, and the best free and open-source FreshBooks alternatives in 2026, including ones you can self-host.
Read →Invoice vs Receipt: What's the Difference (and When to Send Each)
Invoice vs receipt: what each document is, how they differ, and exactly when to send which. A plain-English guide for freelancers and small businesses.
Read →Invoice Ninja Alternative: Inkvoice vs Invoice Ninja (2026)
Looking for an Invoice Ninja alternative? An honest Inkvoice vs Invoice Ninja comparison for 2026: features, footprint, self-hosting, and when each one wins.
Read →How to Write a Late-Payment Reminder (With Email Templates)
How to chase an overdue invoice without burning the relationship: a polite, escalating reminder cadence plus three copy-paste email templates for freelancers.
Read →The Best Open-Source Invoicing Software in 2026
The best open-source, self-hostable invoicing software in 2026: Inkvoice, Invoice Ninja, InvoicePlane, Crater and Akaunting compared on features, footprint, and ease of self-hosting.
Read →QuickBooks Alternative for Invoicing (Free & Lightweight, 2026)
Looking for a QuickBooks alternative just for invoicing? Why it's overkill for many freelancers, what to look for, and the best free, lightweight QuickBooks alternatives in 2026.
Read →Self-Hosted Invoicing with Docker (Coolify & Dokploy Guide)
Self-host your own invoicing app with Docker in minutes: a step-by-step guide using Inkvoice on plain Docker, Coolify, or Dokploy, including the env vars and volume that actually matter.
Read →Zoho Invoice Alternative: Own Your Data in 2026
Looking for a Zoho Invoice alternative? Why people leave, what to look for, and the best alternatives in 2026, including open-source tools you can self-host and fully own.
Read →How to Invoice as a Freelancer (Step-by-Step, 2026)
A practical, step-by-step guide to invoicing as a freelancer in 2026: what to put on an invoice, payment terms that get you paid on time, how to send it, and how to chase late payments.
Read →Free Invoice Template (PDF) and How to Make One in Google Docs, Excel or Word
Download four free, print-ready PDF invoice templates, learn how to build your own in Google Docs, Excel or Word, and see exactly what to put on an invoice so you get paid on time.
Read →The Best Free Invoicing Software in 2026
An honest, no-fluff comparison of the best free invoicing software in 2026 for freelancers and small businesses, including the open-source options.
Read →Looking for a Wave Alternative? Here's How to Choose in 2026
Why people switch from Wave, what to look for in an alternative, and the best Wave alternatives in 2026, including free and open-source options you can self-host.
Read →