Use
Standard charts of accounts are recommended in most countries. These are generally created so that the numbers of accounts belonging to the same functional area begin with the same digits. You use the account group in the chart of accounts to indicate this grouping principle.
When you define an account group, you also determine the number interval in which the accounts of this group must lie. When creating a G/L account, the system checks whether the number you entered lies in the predefined number interval.

The account numbers of bank accounts, postal giro accounts, and cash accounts begin with the number 1. The accounts in account group "Liquid funds accounts", to which all of these accounts belong, all lie in the number interval between 100000 and 129999.
If you create a G/L account with this account group, you must select a number from this number interval. Account number 131000 for G/L account petty cash would be rejected as incorrect since it does not fall within the number interval of account group "Liquid funds". However, you could create this account using the account number 101000.
The number intervals for G/L account groups can overlap. As a result, for G/L accounts that you do not want to assign to any special functional area, you can create a separate account group that has a number interval already contained in a different account group.
Integration
You can change the number interval of an account group at a later time. For more information, see hierzu
Changing the Account Group.Prerequisites
In the chart of accounts list, you define the length of the account numbers for the entire chart of accounts. The maximum length is ten characters. For more information, see
Chart of Accounts List.Features
You have the following options when assigning account numbers.
In order to have an orderly display of the account numbers, you should note the following points.
Always use account numbers of the same length.
Use either alphanumeric or numerical account numbers. The system pads purely numeric account numbers with zeroes from the left, and alphanumeric account numbers from the right.

113000 ® 0000113000
1131DB ® 1131DB0000
Activities
To define the number interval for an account group, from Financial Accounting Customizing choose General Ledger Accounting ® G/L Accounts ® Master Data ® Preparations ®
Define Account Group.