> ## Documentation Index
> Fetch the complete documentation index at: https://help.mathership.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Customer Numbers
> Use vendor-specific customer numbers to identify connected customers
# Customer Numbers
Customer numbers help vendors identify customers in their own internal systems.
Use them when you want to match a Mathership customer with an existing customer record in your ERP, accounting, delivery, or order processing system.
## What they are
A customer number is a vendor-specific reference number assigned to a customer.
It belongs to the relationship between:
* Your vendor company
* The customer company
This means the same restaurant can have different customer numbers with different vendors.
Example:
| Vendor | Customer | Customer number |
| ----------------- | --------------- | --------------- |
| Beverage Supplier | Main Restaurant | 4711 |
| Meat Supplier | Main Restaurant | 10045 |
| Wine Supplier | Main Restaurant | W-203 |
## When to use them
Use customer numbers when you want to:
* Identify customers in your internal system
* Match Mathership customers with existing customer records
* Include customer numbers in order documents
* Support accounting or invoicing workflows
* Improve order processing
* Avoid confusion between customers with similar names
## Where they are used
Customer numbers can be used in:
* Customer management
* Customer detail pages
* Vendor-customer relationships
* Order emails
* PDF order attachments
* CSV order attachments
* Internal vendor workflows
Customer numbers are managed by the vendor. They do not change the customer’s own company profile.
## Adding a number
A customer number can be added when you create or link a customer.
To add a number:
1. Go to **Vendors**
2. Open your vendor company
3. Go to **Customers**
4. Add or link a customer
5. Enter the customer number
6. Save the customer relationship
Required fields depend on whether you create a new customer or link an existing one.
| Field | Required | Example |
| --------------- | -------- | --------------- |
| Customer | Yes | Main Restaurant |
| Customer number | Optional | 4711 |
## Updating a number
You can update a customer number later.
To update a number:
1. Open **Customers**
2. Select the customer
3. Open **Customer Details**
4. Edit the customer number
5. Save your changes
After saving, the new number is stored on the vendor-customer relationship.
Updating a customer number affects the relationship for future use. It does not rewrite already generated documents or emails.
## From invitations
Customer numbers can also be added through invitations.
When you invite a customer, you can include a customer number.
If the customer accepts the invitation or follows your vendor company later, Mathership can use that number for the relationship.
Example:
| Field | Example |
| ----------------- | ------------------------------------------------------- |
| Vendor | Fresh Food Supplier |
| Customer email | [restaurant@example.com](mailto:restaurant@example.com) |
| Customer number | 4711 |
| Invitation status | Pending |
When the invitation is activated, the number can be saved on the vendor-customer relationship.
## Avoiding duplicates
Customer numbers should be unique within your vendor company.
This helps prevent duplicate customer records and confusion during order processing.
Example:
| Customer | Customer number |
| --------------- | --------------- |
| Main Restaurant | 1001 |
| Hotel Kitchen | 1002 |
| City Bar | 1003 |
Avoid using the same customer number for multiple customers unless your internal system intentionally allows it.
## Existing customers
If a customer already has a Mathership account, you can link the existing customer company and assign a customer number.
This is useful when:
* The customer already uses Mathership
* You already have the customer in your internal system
* You want to connect the existing account instead of creating a new one
## New customers
If the customer does not yet exist in Mathership, you can create a new customer and assign a customer number during setup.
Mathership can then create:
* A customer user
* A customer company
* A vendor-customer relationship
* The customer number on that relationship
## In order attachments
Customer numbers can be included in order-related documents.
This helps your team process incoming orders correctly.
Examples:
| Attachment | Use of customer number |
| ----------- | ------------------------------------------------- |
| PDF order | Shows customer reference information |
| CSV order | Helps import or match the order in another system |
| Order email | Helps identify the sender/customer |
## Example: Adding during setup
You add a new restaurant customer.
| Field | Example |
| --------------- | ------------------------------------------------------- |
| Customer | Main Restaurant |
| Email | [restaurant@example.com](mailto:restaurant@example.com) |
| Customer number | 4711 |
After saving, the customer is connected to your vendor company with customer number `4711`.
## Example: Updating later
Your internal system changes the customer reference.
| Field | Old value | New value |
| --------------- | --------- | --------- |
| Customer number | 4711 | 4711-A |
After updating, the new number is used for the relationship going forward.
## Example: From an invitation
You invite a customer and enter their existing customer number.
| Field | Example |
| ----------------- | ------------------------------------------------------- |
| Customer email | [restaurant@example.com](mailto:restaurant@example.com) |
| Customer number | 20345 |
| Invitation status | Pending |
When the customer activates the invitation, the number can be linked automatically.
## Best practices
### Use your existing system reference
Use the same customer number that exists in your ERP, accounting, or delivery software.
### Keep references consistent
Avoid changing customer numbers unless your internal system also changed.
### Check before creating a new customer
Before creating a new customer, check whether the customer already exists in Mathership.
This helps avoid duplicates.
### Add known numbers during invitations
When inviting customers, add the customer number if you already know it.
This makes the connection cleaner once the customer accepts.
### Avoid duplicates
Duplicate customer numbers can cause confusion in exports, order processing, and internal communication.
## Common problems
### Number is missing
This can happen when:
* The customer was added without a number
* The customer followed you from the catalog
* The invitation did not include a customer number
* The customer number was not entered yet
You can usually add it later in the customer details.
### Number is wrong
Open the customer detail page and update the customer number.
Make sure the new number matches your internal system.
### Number already exists
If the number is already used for another customer, check whether:
* The customer was already added
* The wrong customer was selected
* Your internal system uses duplicate numbers
* A duplicate Mathership customer was created
### Number does not appear on an old order
Older orders or already generated documents may still show the old information.
New orders should use the updated relationship data.
### Customer cannot see the number
Customer numbers are mainly vendor-side references.
The customer may not see or manage the number directly.
## Related pages
Add a new customer and optionally assign a customer number.
Connect your vendor company to an existing customer account.
View and update customer relationship details.
Invite customers and include a customer number in the invitation.
Review customer information on incoming orders.
Understand how order attachments can include customer reference information.