Migrating between machines

Replacing a laptop, switching from a Mac to a PC, retiring an old machine — eventually you need to move Solid Accounting to a new computer. Because your books live in a .solid file you control, the move is mostly a file-copy operation; reinstalling Solid is the small part.

The simple case — single-user

If you're the only person using the file:

Step 1 — Get the file off the old machine

Three options:

External drive — copy the .solid file to a USB stick or external drive
Cloud sync — drop it in Dropbox / iCloud / Google Drive (you'll move it out of there on the new machine; cloud sync isn't a long-term home for .solid files — see Storage below)
Network transfer — AirDrop on Mac, Quick Share on Windows, or just SCP/rsync over LAN

The .solid file is encrypted at rest. Even if a transfer medium is compromised, the data is safe — but use your password manager to confirm you've got the file's password before you wipe the old machine.

Step 2 — Install Solid on the new machine

Download the installer from solidaccounting.com/download. Run it.

The first time you launch:

Activate license — paste the license key from your purchase confirmation email
Solid validates against the license server (one-time internet connection needed)
After activation, the app is yours on the new machine

Your license is per-tier with a user limit. Standard tier supports up to 3 users, Pro 5, Accountant 10. If you've already activated on the old machine and didn't deactivate, you've used 1 of your seats. Activating on the new machine uses a 2nd. The license server tracks active activations.

To deactivate the old machine: on the old machine, Help → Deactivate License → Confirm. The seat is freed for re-use elsewhere. If you can't get to the old machine (it's broken, lost, or already wiped), email support@solidaccounting.com — we'll deactivate from our side.

Step 3 — Open the file

File → Open → navigate to your .solid file. Enter the password. Your books open exactly as they were on the old machine — same chart of accounts, same transactions, same audit log.

The settings and preferences are stored in the .solid file, so they come along. The new app honors them.

That's the whole migration for single-user.

Multi-user implications

If you're running multi-user mode, the move depends on which role the migrating machine plays.

Migrating a client machine

If your old machine was just a client (connecting to someone else's host):

Install Solid on the new machine
Activate the license
Connect to the same host via auto-discovery
Done — you don't have a .solid file to move; the host has it

The license seat tracking is per-machine, not per-user — if you migrated, the old machine seat needs to be freed for the new one to count.

Migrating the host machine

If your old machine was Hosting (other users connect to it):

Stop hosting on the old machine — Settings → Multi-User → Stop Host Mode. Connected clients are notified.
Copy the .solid file to the new machine (any of the methods above)
Install Solid on the new machine, activate the license, open the file
Enable Host Mode on the new machine
Clients on your LAN auto-discover the new host (mDNS handles this); they connect automatically

The brief gap when no host is running means clients can't do anything — coordinate the move during off-hours or a planned maintenance window.

Migrating to a Dedicated Server

If you're moving from Host Mode (a workstation) to a Dedicated Server:

Stop hosting on the workstation
Copy the .solid file to the server machine (NAS, dedicated VM, etc.)
Install the headless Solid server build on the server
Activate the license (same key — Solid recognizes the server build under the same license)
Start the server pointing at the .solid file
Clients reconnect via auto-discovery; the server takes over the role

This is a one-way migration in practice — once you have a Dedicated Server, you typically don't go back to Host Mode. The Dedicated Server runs 24/7 without depending on a user's laptop being open.

Cloud Backup considerations

If you have Cloud Backup enabled:

The backup configuration is stored in the file's settings. After moving the file, Cloud Backup needs to be reconfigured on the new machine because secret material (the wrapped BEK) has machine-specific keychain entries.
Settings → Cloud Backup → Reconfigure — re-enter your login password to unwrap the BEK on the new machine
The new machine then takes over the backup schedule from where the old machine left off
Existing backups remain restorable from the new machine

If you don't reconfigure, backups stop running. The status indicator in the new machine's status bar shows the broken state until you fix it.

Storage — where to keep the .solid file

The .solid file is just a file; you can store it anywhere. But:

Local disk — fine for single-user. Pair with a Cloud Backup plan for offsite protection.
External drive — works but the drive needs to be mounted to open the file. Slow over USB 2.0 for large files.
Network share (NFS, SMB) — fine for single-user remote access; for multi-user, use the Multi-User mode instead of having clients open the same file off a share.
Dropbox / iCloud / Google Drive — works but with caveats. The cloud-sync client may upload partial blocks while you're saving, leading to sync conflicts. Cloud-sync folders are in the auto-warning list during Cloud Backup setup for this reason. For single-user with infrequent saves, it works; for multi-user or active editing, prefer local storage.
NAS — good for Dedicated Server scenarios; the NAS can run the headless server build directly.

Transferring the license to a different person

A license is not transferable to a different owner via the migration process — that's a separate license-transfer procedure. If you're handing your business and books to someone else (sale, succession, etc.):

Contact support@solidaccounting.com with the new owner's information
We initiate the license transfer
The new owner activates with the same key on their machine
You're removed from the licensee record

The .solid file goes wherever the new owner decides; transferring the file is just a file copy as above. Transferring the license is the regulatory bit that needs our involvement.

Common gotchas

File won't open on the new machine — "wrong password" or "corrupted file." Double-check the password (your password manager has it). If the password is right, the file may be partially copied — the source's full size on disk should match the destination. Re-copy with verification (rsync -c, robocopy /v) if you suspect corruption.

License activation fails — "too many activations." Old machine wasn't deactivated. Either deactivate it (if accessible), or email support to deactivate from our side. The error message includes the activation count and your tier's limit.

On the new machine, fonts or layouts look different. Solid uses system fonts; macOS and Windows render slightly differently. Functionality is identical; cosmetic differences are normal. Settings → Display has size adjustments if needed.

Multi-user clients can't find the new host. mDNS (auto-discovery) only works on the same physical LAN. If the new host machine is on a different subnet (different VLAN, different physical office), clients need either VPN access or manual IP entry. See Multi-User → Beyond the LAN.

Cloud Backup says "destination unreachable" after move. The keychain entries on the old machine had the credentials Solid was using. After move, Settings → Cloud Backup → Reconfigure re-wraps the BEK with the new machine's keychain.

File is in a Dropbox folder — sync conflict on the new machine. Move the file out of Dropbox to a regular folder. Dropbox's sync isn't compatible with Solid's writes for actively-edited files. Use Cloud Backup instead for offsite protection — same goal, conflict-free.

A clean move checklist

For a planned migration:

☐ Pick a maintenance window (multi-user only) and notify users
☐ Run a Cloud Backup verification on the old machine (proves backups are intact)
☐ Note the .solid file's location and password
☐ Stop Host Mode (multi-user only)
☐ Copy .solid file to portable medium (USB, network)
☐ Old machine: Deactivate License
☐ New machine: Install Solid Accounting
☐ New machine: Activate License
☐ New machine: Copy .solid file to permanent location
☐ Open file, verify books look correct (random check on trial balance)
☐ New machine: Reconfigure Cloud Backup (enter login password)
☐ New machine: Enable Host Mode (multi-user only)
☐ Verify clients can reconnect
☐ Run a manual Cloud Backup to confirm the new machine is the active source

The whole thing typically takes 30 minutes for single-user, an hour or two for multi-user.

Cross-references

Installation — installing Solid Accounting on a new machine
Cloud Backup — offsite backup that survives machine moves
Multi-User — Host Mode and Dedicated Server roles
Account & Billing — License keys — license activation details (when written)