What "Client–Server Multi-User" Really Means
In QuickBooks Desktop multi-user mode, you have one machine acting as the host (the server) and several client PCs. The host stores the live company file (.QBW) and runs the QuickBooks Database Server Manager (QBDBMgrN), which coordinates safe, simultaneous access. The clients run the QuickBooks application and open the same .QBW file via a network path. Only the host should be "hosting." Workstations must not host; this "one host, many clients" rule prevents the common H-series errors (H101/H202/H505). [1]
Why This Model Works Best on a LAN
A Typical Small-Office Scenario
D:\QBData.Plain-English Network Picture
Terminology You'll See Once (So Everything Else is Easy)
What You'll Need (At a Glance)
Step-by-Step on the Host (Do This Once)
- 1Create a clean data path and share it
- Create
D:\QBData. - Share it as
\\HOST\QBData. - Grant your accounting users/groups Modify on the share.
- On NTFS, grant those same users Modify and ensure the QuickBooks service account (e.g., QBDataServiceUserXX) has access. Using Full Control for that service account is acceptable when in doubt. [1]
Share vs NTFS in Plain English
The share permission is the "front door lock." NTFS is the lock on the filing cabinet inside. Users need keys to both. - Create
- 2Install the Database Server Manager (DBSM)
Run the QuickBooks installer on the host → choose Custom or Network Options → pick the option that matches your plan:
•"I'll be using QuickBooks Desktop on this computer, and I'll be storing our company file here …" (host + occasional admin use), or•"I will NOT be using QuickBooks Desktop on this computer." (pure database host).This installs the QBDBMgrN services and the tools you need for LAN hosting. [2]
- 3Scan the data folder (creates/maintains the .ND)
Open QuickBooks Database Server Manager → Scan Folders → add
D:\QBDataand scan. This seeds or refreshes the.NDfile with the host name and port for each company file. [2] - 4Open the right firewall rules once (and be done)•In DBSM → Port Monitor, note the dynamic TCP port for your QuickBooks year (2019+ uses a unique port per year). Create inbound (and, if needed, outbound) Windows Firewall rules for that port.•Also allow QBCFMonitorService, which uses TCP 8019. If you run multiple QuickBooks years on the same host, you'll have one dynamic port per year (and one .ND per company/year). [3]
Don't Guess Ports
Always read them from Port Monitor so you open exactly what QuickBooks needs, no more, no less. [3] - 5Place the company file and seed the .ND
Copy
Company.qbw(and its.tlg, etc.) intoD:\QBData. Launch QuickBooks on the host, open the company in multi-user mode once, then close it. This puts a fresh.NDnext to the file that points clients to the correct host/port. [1,2] - 6Turn hosting ON only on the host
In QuickBooks on the host, go to File → Utilities. The menu should show "Stop Hosting Multi-User Access" (meaning hosting is enabled). If you see "Host Multi-User Access", click it to turn hosting on. [1]
Step-by-Step on Each Workstation (Clients)
- 1Install the same QuickBooks year
[1]
- 2Ensure hosting is OFF
In File → Utilities, ensure you see "Host Multi-User Access" (available). If you see "Stop Hosting …", click it—workstations must not host. [1]
- 3Open the company file from the network
Open the company file from
\\HOST\QBData\Company.qbw(or map a drive that points to the same share). Check "Open file in multi-user mode" the first time. - 4Verify concurrent access works
Verify two people can work at once (if you try to Switch to Single-User Mode, QuickBooks should warn others are connected—that's expected).
UNC vs Mapped Drive
\\HOST\QBData\…) is explicit and avoids letter conflicts. Mapped drives are fine if consistent, but they still resolve to UNC under the hood. If a workstation says "can't find the path," test with ping HOST and fix DNS or the mapping.Deep-Dive: Permissions That Actually Work (and Why)
QuickBooks needs to read and write the .QBW, create/update the .TLG transaction log, and maintain the .ND network descriptor. That means Modify on both the share and NTFS is the safe default. If you do per-user permissions:
How to Verify Quickly
\\HOST\QBData and delete it. If either action fails, fix share/NTFS permissions before you involve QuickBooks.Firewalls and Ports (Why They Matter and How to Set Them Once)
QuickBooks Desktop (2019+) uses a year-specific dynamic port. The Database Server Manager publishes which port belongs to which year. Workstations contact the host using that port plus QBCFMonitorService on 8019. If firewalls block these, you'll see H-errors and connection timeouts.
Steps You'll Perform Only Once on the Host
- 1Check Port Monitor
Open DBSM → Port Monitor → read the port for your year.
- 2Create firewall rules
Create Windows Firewall rules for that port (TCP) and for 8019.
- 3Add program exceptions
If you also run endpoint security/AV, add the QuickBooks executables from Intuit's list as program exceptions. [3]
Sanity Tests (No Tools Required)
ping HOST by name and then by IP. Name-fail but IP-success = DNS problem. Fix DNS or add a temporary HOSTS entry.\\HOST\QBData in File Explorer. If browsing is slow or fails, fix networking before blaming QuickBooks.Ten-Minute Go-Live Checklist
Use Literally at Cutover
Follow this checklist during your go-live to ensure everything is configured correctly.
- 1.Host patched;
D:\QBDatacreated and shared. - 2.DBSM installed; Scan Folders completed for
D:\QBData. [2] - 3.Port Monitor checked; firewall rules for dynamic port and 8019 created. [3]
- 4.Company placed in
D:\QBData; opened once on host in multi-user;.NDregenerated. [1,2] - 5.Hosting ON on the host; OFF on all workstations. [1]
- 6.Two workstations open the same file concurrently via UNC.
- 7.Basic name/IP pings pass; file operations in
\\HOST\QBDatasucceed from clients.
Troubleshooting H-Series (H101/H202/H505) Without Guesswork
Follow Intuit's current checklist and you'll resolve almost every case:
ping HOST must work by name; if not, fix DNS or mappings. [4]Clue-Based Fixes
Error mentions H202/H505 immediately → usually hosting/ports/name resolution.
Can browse \\HOST\QBData but opening the company stalls → check .ND and DBSM service for the correct year.
Works by IP but not by name → DNS/WINS/hosts problem.
Ongoing Care and Feeding
The boring stuff that prevents outages:
Common Pitfalls and How to Avoid Them
NAS Temptation
Hosting the live .QBW on a NAS is a top cause of instability. Keep it on a Windows host's local NTFS disk. [1]
Random Ports
QuickBooks uses dynamic ports by year. Always read from Port Monitor; don't guess. [3]
Multiple QuickBooks Years
Each year has its own QuickBooksDBXX service and port. Make sure the correct year is installed on the host and the workstations that need it. [2,3]
"It Worked Yesterday!"
Check if someone toggled hosting on a workstation, a firewall/AV update tightened rules, or the .ND became stale. The five-step H-series flow above resolves most regressions. [4]
FAQ (Short and Practical)
Q: Do I really need the Database Server Manager if the file is on a Windows server?
A: Yes. DBSM manages locking, advertises the correct port, and maintains the .ND. Install it on the host and scan the folder. [2]
Q: Is a mapped drive required?
A: No. Use the UNC path (\\HOST\QBData\Company.qbw). Mapped drives are okay if consistent, but UNC avoids letter conflicts and clarifies which host you're using. [1]
Q: How do I know the right port?
A: Open DBSM → Port Monitor and read the year's dynamic port. Then create firewall rules for that port and for 8019 (QBCFMonitorService). [3]
Q: Which Windows versions are supported in 2025?
A: For QuickBooks Desktop 2024, Intuit lists Windows Server 2016/2019/2022 on the server side and 64-bit Windows on clients. Always check your exact year's system requirements. [4,5]
Q: What's the fastest way to prove multi-user is healthy?
A: Open the company on the host once (to refresh .ND), then open it from two workstations via UNC. Try to switch one workstation to Single-User; you should be warned another user is in the file.
Who Does What (Roles at a Glance)
IT/Server Admin
D:\QBDataAccounting Lead
All Users
Final Cutover Script
Read Aloud on Go-Live Day
- 1."Host is ready and scanning
D:\QBData. Hosting is ON on the host and OFF on all PCs." - 2."Firewall is open for the year's dynamic port and for 8019."
- 3."We'll open the company on the host once, then close."
- 4."Now each workstation opens
\\HOST\QBData\Company.qbwin multi-user." - 5."We confirm two people can edit simultaneously and that switching to Single-User warns about other users."
- 6."We run a small test: create a dummy vendor bill and delete it—on both workstations—so we confirm write permissions."
References
All procedures and recommendations in this guide are verified against official Intuit documentation:
- Host your company data in multi-user mode in QuickBooks Desktop (concepts, hosting rules, multi-user overview)
- Use QuickBooks Database Server Manager (scan folders, .ND, service fundamentals)
- Install QuickBooks Database Server Manager
- Set up firewall and security settings for QuickBooks Desktop (dynamic port by year, executables, 8019)
- Fix Error H202/H505 (official troubleshooting flow for multi-user connectivity)
- System requirements — QuickBooks Desktop 2024 (supported Windows versions; sizing guidance)
Conclusion
This definitive, fact-checked guide provides everything you need to successfully set up QuickBooks Desktop in multi-user mode on a LAN. By following these documented, official procedures, you can deploy a robust QuickBooks environment that supports concurrent users reliably.