> ## Documentation Index
> Fetch the complete documentation index at: https://docs.m3ter.com/llms.txt
> Use this file to discover all available pages before exploring further.

# FAQs: Configuration and Setup - Best Practices

> Answers to questions on configuration setup in m3ter. Learn when to use one Meter or two and how to structure Products for accurate accounting and billing.

## Question: When to use one Meter and when to use two?

One Meter is sufficient when the source data does not change.

Aggregations *(including compound aggregations)*, segmentation and pricing can then be leveraged to create different data summaries and price points. As a general rule, you should use a single Meter with multiple Data Fields when the data being collected is of a similar or related type. For example:

* Suppose you want to charge your end customers on the basis of the number of logins they make and where they are logging into your service from. You could create a single Meter and define two non-numeric Data Fields: a *Who* Data Field to collect the required data for login counts on specific users; a *Where* Data Field for collecting the location of logins.
* However, you might also want to charge your customers on the basis of the volume of data they upload to store on your service during a given billing period. You should then create a second and separate Meter with a numeric *Measure* Data Field to sum each customer's quantity of data stored.

***

## Question: Should you have one Product or two?

Typically you would create a Product per accounting code in your accounts receivables (AR) system. This way, when integrating with the AR, m3ter knows which Product to assign to the invoice line so that revenue for the product/service can be easily identifiable and recognized.

To ensure Bill line items are assigned to the correct Product lines, you can select an *Accounting Product* when configuring many of the billing-related entities used to set up pricing and charges in your m3ter Organization.

<Warning>
  **More Details?** See [Bill Line Items - Mapping to Accounting Products](/guides/billing-and-usage-data/running-viewing-and-managing-bills/bill-line-items-mapping-accounting-products).
</Warning>