Definition
A customer account number is a unique code a seller assigns to each client to identify them across invoices, statements, and payments. It stays the same for every transaction with that client, unlike an invoice number, and helps match payments and records when clients have similar names or several locations.
Also called: Customer ID, Account number, Client number
Customer account number in practice
Print the customer account number on every invoice and statement, and ask clients to include it with payments. It is especially helpful for utilities, subscriptions, and suppliers with many customers.
Frequently Asked Questions
Is a customer account number the same as an invoice number?
No. The invoice number changes with every invoice. The customer account number identifies the client and stays the same across all of their invoices.
How should I format customer account numbers?
Use a simple, consistent format, such as a short prefix and a sequential number (CUST-0042), and avoid personal data like phone numbers. Assign the number once when you add the client and never reuse it for someone else.
Related terms
- Invoice number An invoice number is a unique identifier assigned to each invoice so it can be tracked, referenced in payments, and audited.
- Reference number A reference number is any identifier placed on an invoice or payment to connect related records, such as the client's project code, a contract number, or the text the client should put in their bank transfer so the payment can be matched to the invoice.
- Statement of account A statement of account is a summary document that lists all invoices, payments, and credits between a seller and one client over a period, ending with the current balance owed.
- Accounts receivable Accounts receivable is the total amount of money owed to a business by its clients for invoices that have been issued but not yet paid.
This page is for general information only and is not legal, tax, or financial advice. Rules change and vary by location, so consult a qualified lawyer or accountant about your situation.