Import clients from Excel or CSV: prepare a clean file before migration

Before editing your client file, create a copy. Keep an original dated version, then work on a cleaning version. This lets you go back if you delete a useful column or create an error while correcting data.

A simple name is enough: `clients-original-2026-07.xlsx` for the archive, then `clients-to-import.xlsx` for the prepared file.

This habit is especially useful when the file contains several years of history or important business notes.

The goal is not to import everything that exists. The goal is to import what will be useful in the new tool.

The most important columns are usually:

Avoid ambiguous columns such as “info,” “misc,” “old” or “to check” without explanation. If one column contains several types of information, split it before importing.

Duplicates are common. The same client may appear in several forms: `Acme`, `ACME SA`, `Acme Studio`, `Acme - old contact`. Before importing, choose a naming rule.

You can keep the legal name for invoicing and use a note for the commercial name if needed. What matters is that the client is easy to find later.

To detect duplicates, sort by name, email or email domain. Pay special attention to clients who changed contacts or addresses over time.

A client file becomes difficult to use when addresses follow no logic. Some countries are written in French, others in English, some as abbreviations. Some cities include accents, others do not. Some postal codes are stored as numbers and lose leading zeros.

Before importing, choose a consistent format. For example:

This consistency makes invoice generation and future searches easier.

Email is often the most important field after the name. It is used to contact the client, send an invoice or find the relationship again.

Check simple errors: spaces before or after the address, typos, old emails, personal contacts that should be replaced with billing addresses.

If a client has two useful email addresses, do not mix them in the same cell without a rule. Create `contact_email` and `billing_email` instead if your tool supports it.

An old file may contain information that is useless or too sensitive for your new database: personal notes, obsolete comments, abandoned prospecting columns, unverified data.

Before migration, ask whether each column has operational value. If it does not help manage the client, a project, an invoice or follow-up, it may not need to be imported.

This keeps the new database cleaner from the start.

When possible, test the import with a few rows before importing the whole database. Choose varied cases: a simple client, a client with a full address, a client with a billing email, an international client, a client with notes.

After the test, check:

A five-row test can prevent a manual cleanup of two hundred records.

Importing clients from Excel or CSV is a good opportunity to start from a clearer base. The point is not only to move data. It is to transform a historical file into a usable database for projects, services, expenses and invoices.

Kronoma lets you import clients from Excel or CSV files so you can start faster with a cleaner and more useful client base.