Deregister FileZilla Pro from a computer before you wipe, reformat, or replace it. Your license only allows a limited number of active registrations at once, and reinstalling your operating system or moving to a new machine doesn’t automatically free up the slot the old install was using. If you skip this step, you might get the “registration limit exceeded” message when you try to activate FileZilla Pro on the new machine, even though the old one is gone. Deregistering first takes under a minute.
Why this happens
FileZilla Pro tracks how many devices a single license is currently registered on, and caps that number under its terms. Deregistering tells FileZilla Pro’s servers that a particular installation no longer counts against that limit. Uninstalling the app, wiping the drive, or reinstalling Windows or macOS doesn’t send that signal on its own, so as far as your license is concerned, that registration is still active until you deregister it or contact support.
That’s exactly what shows up repeatedly in our support forum: someone reformats their PC or sets up a new computer, tries to activate FileZilla Pro, and hits the registration limit, not because they are using more devices than their plan allows, but because an old, now-gone install is still holding a slot.
Before you wipe or replace your computer: deregister first
On Windows
- Go to your FileZilla Pro installation folder (typically
C:\Program Files\FileZilla Pro). - Double-click the Deregister FileZilla Pro shortcut.
- Enter your registration key when prompted.
- If FileZilla Pro is still running, close it and try again.
- Click OK to confirm. The registration is now freed up.
Prefer the command line? Open Command Prompt and run (adjusting the install path if yours differs):
"C:\Program Files\FileZilla Pro\filezilla.exe" --deregister --regkey=XXXX-XXXX-XXXX-XXXX-XXXXOn macOS
- In Finder, go to Applications and locate FileZilla Pro.
- Control-click FileZilla Pro and choose Show Package Contents.
- Open Contents > MacOS.
- Open Terminal, then drag the
filezillafile from that folder into the Terminal window — this fills in the full path for you. - With the cursor still at the end of that line, type a space and add:
--deregister --regkey=XXXX-XXXX-XXXX-XXXX-XXXX(using your actual registration key). - Press Enter. That installation is now deregistered.
Full reference with more detail on both platforms: How to Deregister FileZilla Pro.
Already wiped the computer? Here’s what to do
If you’ve already reformatted, reinstalled the OS, or otherwise lost access to the machine before deregistering, contact info@filezillapro.com with your registration key, your order number or the registered email address. Support can reset the stuck registration from their end once they have verified your license.
Quick checklist before you wipe any device running FileZilla Pro
- Deregister FileZilla Pro (steps above) — do this first, before you start the reformat or migration.
- Using FileZilla Pro CLI on that machine too? It has its own separate registration and needs its own deregistration step: How to Deregister FileZilla Pro CLI.
- Retiring a FileZilla Pro Enterprise Server install instead of the desktop client? That is a different process: How to Deregister FileZilla Pro Enterprise Server.
- Keep your registration key somewhere you can find it independent of the machine you are wiping — your Welcome email is the most reliable source.
Frequently asked questions
How many devices can I register FileZilla Pro on at once?
It depends on your plan. If you’re not sure what your current limit is, check your account details or ask info@filezillapro.com before you plan a migration across several machines.
Does uninstalling FileZilla Pro automatically deregister it?
No. Uninstalling the application removes it from your computer but doesn’t free up its registration slot on its own. Run the deregistration steps above before (or instead of) uninstalling if you want that slot back. If you forgot to deregister the software before uninstalling it, you can simply reinstall it and then complete the deregistration process.
What if I don’t have my registration key anymore?
Check the purchase confirmation email from when you bought FileZilla Pro — that’s where it was originally sent. If you can’t locate it, contact info@filezillapro.com and support can look it up against your order or registered email address.
Setting up FileZilla Pro on a new computer? See the Windows install guide or the macOS install guide or the Debian Linux install guide.