HMRC Basic PAYE Tools Won't Open? Database Errors, Mac Updates and Security Warnings Fixed

Basic PAYE Tools usually fails to open after a macOS update, because security software blocks it, or because its database is damaged.

Checked on 25 October 2026. The fixes below come from HMRC's own service issues page (updated 29 September 2026) and its user guide. Fixes from other sources are labelled. We have not tested them ourselves.

Every fix in this table comes from HMRC except the database error. That one comes from a user report.

Who can use Basic PAYE Tools

HMRC's free payroll software is for employers with fewer than 10 employees. GOV.UK says it supports Windows 10 and 11, macOS 15 and 26, and Ubuntu 24.04 and 25.10. All must be 64-bit, with at least 4GB of RAM. The current version shows under Settings, in the top-right corner of the tool.

Fix 1: it won't open after a Mac update

HMRC says some users cannot open the tool after updating to macOS 15 'Sequoia', 26 'Tahoe' or 27 'Golden Gate'. Its workaround runs the tool's built-in server from Terminal:

1. Quit Basic PAYE Tools.
2. Open Terminal and use the cd command to go to the app's rti.app/Contents/MacOS folder.
3. Run ./rti runserver 46729.
4. In your browser, go to http://127.0.0.1:46729/.
5. Keep Terminal open while you work. Do not open the normal app at the same time.
6. Press Ctrl+C in Terminal when you have finished.

HMRC says you must repeat these steps each time you use the tool, until it releases a fix.

Fix 2: security software blocks it

HMRC says security products may warn about a new release because they do not recognise it. Its advice:

• It is safe to bypass the warning and allow Basic PAYE Tools to install, run and submit data.
• Allow the installation file plus rti, bptshell and uninstall in your security software.
• If it still will not launch, run it as an administrator.
• HMRC cannot give steps for specific security products. Ask the security software's maker.

Only download the tool from GOV.UK's download page. Bypassing a warning is only safe for the genuine HMRC file.

Fix 3: "could not access the database"

HMRC's issues page does not currently list a database error. The fix below is a user report from a 2019 sysadmin blog, written for Windows 10. It says the message means the database file is damaged.

1. Back up first, if the tool will open at all. HMRC's user guide says backups save as a .bak file in a location you choose.
2. Find the data folder. The blog gives C:\Users\<your name>\AppData\Roaming\HMRC\payetools-rti.
3. Copy the whole folder somewhere safe before you change anything.
4. Rename the database file (the sqlite3 file). The tool creates a fresh, empty database when it next starts.
5. Restore your .bak backup into the new database from inside the tool.

Without a backup, a fresh database starts empty. You would need to re-enter employer and employee details. If that happens part-way through a tax year, call HMRC's Employer Helpline on 0300 200 3200 before you submit anything.

Moving Basic PAYE Tools to a new computer

HMRC's user guide covers backing up and restoring, but not a move. The usual route, from accountants on AccountingWEB:

1. On the old computer, back up each employer from inside the tool.
2. Copy the .bak files to the new computer.
3. Install the latest Basic PAYE Tools from GOV.UK on the new computer.
4. Restore each backup from inside the tool.
5. Check the year-to-date figures match before your next submission.

The start of a tax year is the easiest time to move, because there is less year-to-date data to carry over.

Correcting a payroll mistake

HMRC's user guide says that if a submission fails, delete it and submit a correction. If the mistake is in your final FPS of the tax year, amend it and send a corrected FPS. For the full rules on correcting an FPS or EPS, see our RTI error codes guide.

Quick answers

Why won't Basic PAYE Tools open on my computer?

• On a Mac, a recent macOS update is the most common cause HMRC lists. On Windows, try allowing it in your security software and running it as an administrator.

Are Basic PAYE Tools still available?

• Yes. HMRC says the tool will work as normal throughout the 2026 to 2027 tax year. It is reviewing the effect of Apple ending support for Intel apps on Apple Silicon Macs from autumn 2027.

How do I transfer data from Basic PAYE Tools to a new computer?

• Back up each employer as a .bak file on the old computer. Then install the latest version on the new one and restore the backups.

How can I correct payroll errors using Basic PAYE Tools?

• Delete a failed submission and submit a correction. For a mistake in the final FPS of the year, send a corrected FPS.

Should I uninstall and reinstall Basic PAYE Tools?

• No. GOV.UK warns that uninstalling your existing version loses your payroll data. Install the new version over the top instead.

Sources, checked 25 October 2026:

• GOV.UK: Basic PAYE Tools service availability and issues (updated 29 September 2026)
• GOV.UK: download HMRC's Basic PAYE Tools
• GOV.UK: Basic PAYE Tools user guide
• GOV.UK: employers general enquiries helpline
• HMRC Community: startup error after the 2025-26 update (April 2025)
• My Sysadmin Tips: "could not access the database" (May 2019)
• AccountingWEB: transferring Basic PAYE data to a new PC (April 2019)