SQL Server 2025 Express on Windows allows 50 GB per database. Every older version of Express, and Express on Linux, stops accepting writes at 10 GB: the app on top errors and there is no dial to turn. If you are on 2022 or older on Windows, upgrading to 2025 may be the cheapest way out, provided the application vendor supports it and your Windows Server version does. Test a restored copy before touching production. The other three are buy Standard, move to Azure SQL, or move the data and the app into Microsoft 365. For firms under 20 staff the Microsoft 365 route is often the cheapest long term, because it removes the server as well as the limit. Checked by Balu at Kove (kove.nz). The SQL migration checklist covers the way out, or book a free 30-minute call if you are deciding what to move it to.
Why small firms run Express without knowing
It came free with something. The job-management product installed it in 2015. The developer who built the bespoke app chose it because it cost nothing. The accounting package needed it. No one made a licensing decision; the software did. Ten years later the database has ten years of jobs, quotes, photos stored as blobs and a log table that grew every night, and one Tuesday the app reports it cannot save. The first thing to check is SELECT @@VERSION, which names the edition on the first line, and the size of the data file in SQL Server Management Studio.
What the limit actually is
- 10 GB per database on SQL Server 2022 and older, and on Express for Linux; 50 GB per database on SQL Server 2025 Express for Windows. Data files only. Logs and FILESTREAM data are outside it. Two databases on one Express instance each get their own limit.
- Also capped, on every version: one socket or four cores, and about 1.4 GB of memory for the buffer pool, which is why the app got slow long before it got full.
- 10 GB from SQL Server 2008 R2 to 2022. Moving between those versions changes nothing. SQL Server 2025 is the first Express release to raise the ceiling, and it dropped the separate Express with Advanced Services download: plain Express now carries those features. Microsoft's What's new in SQL Server 2025 and the 2025 editions table carry the figure, read 3 October 2026.
- No paid updates. Express, Web and Developer editions are not eligible for Extended Security Updates, so an Express 2014 or 2016 instance is unpatched with no paid path, as the SQL Server 2016 post sets out.
- Often on an ageing OS too. A ten-year-old Express instance is commonly still sitting on Windows Server 2016, which stops getting free updates in January 2027.
Buying time, in the order that works
- Before anything else: take a full backup, restore it somewhere else to prove it works, and check whether you have to keep that history for tax or contract reasons. If the database belongs to a packaged product, ask the vendor before you move, archive or delete anything, because the app may expect the data where it is.
- Find what is big. Usually one or two tables: attachments as blobs, a log or audit table, or a history table no one queries.
- Move blobs out. Photos and PDFs stored inside the database go to a file share, a SharePoint library or FILESTREAM, with the path kept in the row. The application has to know how to read them from there, so this is a change to the app as well as the database, not just a data move. Done properly it often halves the file.
- Archive by year. Closed jobs older than three years move to an archive database on the same instance. The limit is per database; the app points at the live one. That only works if the app can still find archived jobs when someone looks one up, so check that first.
- Drop what no one reads, once you have confirmed that nothing reads it. Nightly log tables, failed-import tables, the copy from 2019. Script the table out and keep a backup before you drop it.
- Shrink only if you have to, and last. Freeing space inside the database is what lets writes carry on. Shrinking only hands space back to the disk, it fragments your indexes, and the file grows again if the app needs the room. Microsoft says not to treat it as routine maintenance. If you do shrink, rebuild the indexes afterwards, and do not do it while a backup is running.
How long this takes depends on what is big, which I only know after looking at table sizes. For many small firms it is a day or two of work and it buys months, sometimes years. It is also the moment to decide where the system is going, because the growth that filled 10 GB has not stopped.
The four ways out
The first is a version upgrade. The other three are exits, and they are the ones I would weigh against each other if the system is ageing as well as full.
| Path | What you pay | What you are left running | Right when |
|---|---|---|---|
| Upgrade to SQL Server 2025 Express (Windows) | Nothing for the licence; the upgrade or migration work, and a supported Windows Server underneath | The same server, patched and backed up by you, with the ceiling at 50 GB instead of 10 GB | The vendor or developer supports 2025, and 50 GB is years of headroom. Test on a restored copy first |
| Buy SQL Server Standard | A four-to-five-figure licence (per core, or server plus CALs), plus a supported Windows Server; if the front end is a Power App, NZ$32.40 per user on top | The same server, patched and backed up by you, with the ceiling removed | A vendor product needs SQL Server, or the database is heavy with logic that would not move |
| Azure SQL Database | From tens of dollars a month for a small database, plus migration; no server | A cloud database you still administer, connection strings re-pointed | The app can point at a new connection string and the logic stays in T-SQL |
| Microsoft 365: Dataverse or SharePoint lists | $8,000 to $18,000 fixed for a firm under 20 staff, migration included; licences $0 on SharePoint or NZ$32.40 per user on Dataverse, 10 GB included | No database server to patch, storage pooled across your tenant (10 GB plus 250 MB per Premium licence, with more at NZ$64.70 per GB a month if you outgrow it), a rebuilt front end on phones | The value is in the data and the forms, not the stored procedures, and nobody wants to own a server |
The last row is the one a vendor will not suggest and a large consultancy will not quote at this size. It is the shape of most small-firm Express databases: tables, a front end, a few procedures, and a lot of history. Moving a SQL Server database into Microsoft 365 is the full decision with costs; the load method and the gotchas per source are on the migration hub.
Common questions
What happens when SQL Server Express reaches 10 GB?
Inserts and updates that need new space fail with a could-not-allocate-space error for the PRIMARY filegroup, and the application on top of it starts throwing errors or silently losing saves. Reads keep working. The limit is per database, on the data file only; log files and FILESTREAM data do not count toward it. On SQL Server 2025 Express for Windows the same thing happens at 50 GB.
What is the SQL Server Express database size limit in 2025?
SQL Server 2025 Express on Windows allows a maximum relational database size of 50 GB, up from 10 GB in 2022 and earlier. Express for Linux is still listed at 10 GB on Microsoft's 2025 Linux editions page. Express with Advanced Services is discontinued in 2025, and plain Express now includes those features. Source: Microsoft Learn, What's new in SQL Server 2025, read 3 October 2026.
Can I increase the SQL Server Express database size limit?
On Windows, yes, by moving to SQL Server 2025 Express, which allows 50 GB per database. On SQL Server 2022 and older, and on Express for Linux, no: 10 GB per database has been the ceiling since SQL Server 2008 R2. The ways past it there are upgrading to 2025, buying Standard edition, moving to Azure SQL Database, or moving the data somewhere that is not SQL Server, such as Dataverse.
How do I buy time on a full Express database?
Archive old rows to a second database (the limit is per database, so two 9 GB databases are legal), move attachments and images stored as blobs out to files or FILESTREAM, take a restorable backup first, then delete the logging tables nobody reads, and only shrink if you must, rebuilding indexes afterwards. That typically buys months, sometimes years. It does not fix the underlying fact that the system is growing past what its licence allows.
Is moving to Dataverse cheaper than buying SQL Server Standard?
Often for a firm under 20 staff, but it depends on the front end. Standard is a four-to-five-figure licence plus a supported Windows Server. If you keep the existing front end, you pay nothing for Power Apps. If you want a modern Power App on top of either, you need Power Apps Premium at NZ$32.40 per user per month on both routes, because the SQL Server connector is premium. Worked example for 12 users on Dataverse: 12 x NZ$32.40 x 12 months is NZ$4,665.60 a year, with 10 GB plus 250 MB per licence of storage, no server, and a build of $8,000 to $18,000. Put that beside a real quote for Standard and the Windows Server under it before deciding.
Where to start
Send me the first line of SELECT @@VERSION and the data file size. One free 30-minute call and you know how much time the clean-up buys and which of the four ways out fits, priced.