> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chatsyncs.com/llms.txt
> Use this file to discover all available pages before exploring further.
# How to Import Subscribers Using CSV
> Step-by-step guide to bulk-importing subscribers into ChatSyncs from a CSV file — the required phone_number/name columns, the common Excel scientific-notation bug that corrupts phone numbers and how to fix it, mapping columns to ChatSyncs fields, and how any extra column becomes a custom field automatically.
## When to use CSV import
Use CSV import when you already have a spreadsheet of contacts — exported from another tool, a
sales list, an event sign-up sheet — and want to bring them all into ChatSyncs at once, instead
of adding them one at a time or waiting for each person to message the bot first. It's the
fastest way to seed [Subscriber Manager](/learn/whatsapp-subscriber-manager) with an existing
contact list.
Already have subscribers in ChatSyncs and want to go the other way? **Options →
Download(all) as CSV** on the Subscriber Manager list exports the current list as a CSV file —
handy for editing offline before re-importing, or for a backup.
Only have a handful of contacts, or contacts already living in a Google Sheet or your Google
account? See [Import Subscribers Manually](/learn/subscriber-manager-import-manually) or
[Import from Google Sheets](/learn/subscriber-manager-import-google-sheets) instead.
## Import a CSV file
From the Subscriber Manager list, open **Options**, then **Import Subscribers**.
Select the CSV upload option in the modal shown above.
At minimum, your CSV needs a phone number column and a name column — see the table below. A **Sample CSV** link in the modal shows the exact expected format.
Select your prepared CSV file to upload it.
Match each column in your file to a ChatSyncs field — see "Map the columns" below.
Click **Confirm** — the imported contacts appear in the Subscriber Manager list.
## The CSV format
A CSV needs at minimum a phone number and name column, e.g.:
| phone\_number | name |
| ------------- | ------ |
| 919876543210 | User 1 |
| 919876543211 | User 2 |
**Country code is mandatory, and the phone number must be plain digits** — e.g. `919876543210`,
not `+91 9876543210` or a locally-formatted number. A number missing its country code, or
formatted with symbols and spaces, will fail to match the right subscriber.
**Format the phone number column as plain numbers or text before exporting to CSV** — Excel
often displays long phone numbers in scientific notation (e.g. `8.8E+12` instead of
`8801710000000`), and a CSV exported in that state will import garbled or truncated numbers.
Fix it in Excel with **right-click → Format Cells** on the column, set it to **Number** with
**0 decimal places** (or **Text**), before saving as CSV:
## Map the columns
After uploading, map each column from your file to a ChatSyncs field:
* Map `phone_number` → **Phone Number**.
* Map `name` → **Subscriber Name**.
* Verify every mapping carefully before confirming — a wrong mapping imports the wrong data into
the wrong field for every row.
Any extra column beyond phone number and name is treated as a **[custom field](/learn/subscriber-manager-custom-fields-and-labels#custom-fields)**
automatically. If the subscriber already exists (matched by phone number), that custom field is
updated on the existing record; if not, a new subscriber is created with it already filled in.
**Expected result:** Every row in your file becomes a subscriber in Subscriber Manager, with
extra columns populated as custom fields — ready to label, message, or enroll in a sequence
immediately.
## Frequently asked
A `phone_number` column and a `name` column. Any other column is imported automatically as
a custom field.
Excel often displays long phone numbers in scientific notation (`8.8E+12`). Format the
phone number column as **Number** (0 decimal places) or **Text** — right-click → **Format
Cells** — before saving the file as CSV, or the import will bring in the garbled value.
The existing subscriber record is matched by phone number and updated — any new custom
field columns are added or overwritten, rather than creating a duplicate.
Yes — the country code is mandatory and the number should be plain digits with no `+` or
spaces, e.g. `919876543210`.
Yes — the Import Subscribers modal has a **Sample CSV** link showing the exact expected
column layout.
## Related Documentation
* [Subscriber Manager](/learn/whatsapp-subscriber-manager) — the subscriber list, Options menu,
and Download(all) as CSV.
* [Custom Fields and Labels](/learn/subscriber-manager-custom-fields-and-labels) — how imported
columns become custom fields.
* [Import Subscribers Manually](/learn/subscriber-manager-import-manually) — for adding one
contact at a time instead.
* [Import from Google Sheets](/learn/subscriber-manager-import-google-sheets) — for importing
without exporting a CSV file first.