Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE Accounts ( customer_id VARCHAR )
TABLE: CREATE TABLE Customers ( customer_id VARCHAR )

### Question ###
Show the number of all customers without an account.

### Accurate SQL ###

SELECT COUNT(*) FROM Customers WHERE NOT customer_id IN (SELECT customer_id FROM Accounts)