Importing customers

Sliptree can import your customer list from a spreadsheet. This article covers file requirements, column mapping, the Update existing option, and what to do if some rows fail.

File format and size

You can upload a customer list in CSV, XLSX, or ODS format. The file must be 10 MB or smaller. The first row should be a header row with column names — Sliptree uses these to suggest mappings automatically.

If you don't have a file yet, download our sample CSV to see the expected shape. Any column order works — Sliptree maps columns by their header name, not by position.

To start an import, open the Customers page and click Import customers.

Required and optional columns

Sliptree supports the following columns. Only Name is required — everything else is optional and can be filled in later.

Column	Required	Notes
Name	Yes	Customer or company name.
E-mail	No	Used to send invoices and estimates.
Address, Address 2, City, State, Postal code, Country	No	Country should be the ISO 2-letter code (e.g. `EE`, `GB`, `US`) or the localised country name.
Registration number	No	Company registry number.
VAT number	No	The country prefix (e.g. `EE`, `DE`) is added automatically when missing.
Phone, Website	No	Free-form text.
Invoice payment terms, Estimate expiration	No	Number of days.
Late fee rate	No	Annual percentage.
Currency	No	Three-letter code (e.g. `EUR`, `GBP`, `USD`).
Locale	No	Language for emails and documents (e.g. `en`, `et`).
ID	No	Your own external identifier — useful when syncing from another system.

Columns in your file that don't match any of the above can be skipped during mapping — they won't be imported and the import proceeds without them.

Column mapping with auto-detection

After you upload the file, Sliptree shows the Column mapping step: each column from your spreadsheet on the left, and a dropdown of Sliptree fields on the right.

Column mapping step in the customer import dialog — source columns from the CSV on the left, Sliptree field dropdowns on the right, auto-mapped where the header name matched

Sliptree tries to match each column automatically based on the header name, including common variations:

address, address1, address_1, street_address, street_address_1 → Address
address2, street_address_2, apartment → Address 2
postcode, zip → Postal code
e-mail, e_mail → E-mail
registration, registry_nr, registration_number → Registration number
vat, vat_nr, vat_number → VAT number
title → Name

If a column was matched correctly, you don't need to do anything. If it wasn't, pick the right field from the dropdown — or pick — Skip this column — to ignore it. Each Sliptree field can only be used once, so the dropdown grays out any field that's already taken.

The Name field is mandatory — at least one column must be mapped to it before you can continue.

Update existing customers

Below the column mapping, there's a single checkbox: Update any customers that already exist.

Off (default) — every row creates a new customer. If a row matches an existing customer (by name or email), it's added as a duplicate. Use this for a clean one-time import into an empty account.
On — rows that match an existing customer update that customer's details instead of creating a duplicate. Empty cells in the file leave the existing values alone, so you can update just a few fields without retyping everything else.

Turn this on whenever you're re-importing a list to refresh stale data, or when your source file might overlap with customers you've already added manually.

After the import

Imports run in the background — for small files this is instantaneous, for larger ones you'll see a progress indicator. When it's done, Sliptree shows a summary:

How many customers were imported.
How many rows failed, if any.

You'll also get an email with the same summary once the import finishes, which is handy for larger files where you might navigate away.

Fixing failed rows with the error report

If any rows failed validation — for example, a malformed email or an unrecognised country — the summary includes a Download the error report link. The report is a CSV containing only the failed rows, with an extra column explaining what went wrong on each line.

The usual workflow is:

Download the error report.
Fix the issues in the report file (or in your original spreadsheet).
Start a new import with the fixed file.

Importing the error report directly is fine — the successful rows from the first run are already in your account and won't be duplicated as long as you leave Update existing off and the error rows weren't created in the first run.

Exporting customers — the reverse direction, including using an export to bulk-edit and re-import.
Importing products — the same workflow, applied to your product catalogue.