The change log: who changed what?

When a bank account number or a payment term has suddenly changed, you want to know who changed it, when, and from what to what. The change log in Business Central can answer, but it has to be set up with care, because it can affect performance and take up space in the database. The article shows how to set it up, what you should log and how to keep the log under control. There is also a short checklist.

The change log and its setup

The change log records direct changes that users make to data in the tables and fields you have chosen. You can see inserts, modifications and deletions on the Change Log Entries page, sorted by time, with user, old value and new value.

Changes only appear once the user's session has been restarted, for example by switching company or signing in again. That is worth knowing when you test.

Open the Change Log Setup page and turn the log on. Then choose the action Tables and specify which tables you want to track and which kinds of changes should be logged. For each table you choose whether all fields or only some fields are followed.

You can also analyse the log with data analysis directly on the page, for example as a view of who has changed what and when.

Log little, but the right things

Microsoft Learn warns that tracking can affect performance and increase the size of the database, which can cost money. Microsoft therefore recommends being careful in choosing tables and actions, not adding G/L entries and posted documents, and choosing selected fields instead of all fields.

Posted entries cannot be changed in the same way anyway, so there is less to gain from logging them.

Customer and vendor cards: bank details, payment terms, blocking.
Setup tables: VAT, posting groups and number series.
Item card: costing method and unit prices, if that is an issue.
User setup and permissions, if you need an audit trail.

Monitor sensitive fields

For individual fields, for example the company's IBAN, you can use field monitoring instead. You get an email when someone changes the value. The setup runs through a guide, and the sender account must be of the type Microsoft 365 or SMTP, not the current user.

If a field is monitored, the table cannot at the same time be set up in the change log.

Retention and limitations

The log grows. Create a retention policy that deletes entries older than a period you choose. Ask your auditor how long you need to be able to document changes, and check the requirements with your local authority before you choose the period.

Use the same policy for the monitoring log. Remember that clean-up also frees space in your data capacity.

The change log does not log fields with the autoIncrement property. It is also switched off during an upgrade of Business Central to make the upgrade faster. Changes made by code in extensions can behave differently from user changes, so test with a specific situation.

Analysis and telemetry

On the Change Log Entries page you can turn on analysis mode and drag fields such as user, time, table, field, old value and new value into the view. You can make fixed tabs for questions such as who changed what, and which changes have happened in a particular table.

Save the views, so that the auditor or the finance director can open them without help.

Changes to the change log setup itself can be sent to Application Insights as telemetry, if you have set it up. Then you can see if someone switches off logging or removes a table, and get an alert. That is a useful control if audit trails matter for your accounts.

Help

Addverk is a new Business Central partner. See our services and prices if you want help designing an audit trail.