Purchase / Sales ledgers are required for trading, repacking or for usage in manufacturing products. Sales and Purchase account groups are meant for revenue accounts and are reflected in the Profit & Loss Account.
To create a Purchase / Sales Ledger,
Go to Gateway of Tally > Accounts Info > Ledgers > Create
Inventory values affected: This is applicable for Companies maintaining Accounts with Inventory. Inventory allocation is required for Accounts like Sales, Purchase, Receipt note, Delivery note, etc. However, Tally.ERP 9 does not restrict to particular accounts as you may have the need to affect inventory with accounts like Customs Duty, and perhaps, direct expenses related to purchases such as Freight Inwards.
Cost Centres are applicable: Tally's concept of Cost Centres allows an additional dimension to a transaction. .
You have set Maintain Cost Centres to Yes in F11: Features:F1:Accounting Features, to get this option in the Ledger creation screen. If any of the transactions need to be allocated to any particular Cost Center (Which involves this ledger) set this option to Yes.
Activate Interest calculation: Set this option to Yes to enable Tally.ERP 9 to calculate interest automatically based on the interest rate and style of calculation specified for this ledger account.
Use advanced parameters: The advanced parameters are particularly useful where interest rates change from time to time. Set this option to Yes to enable this.
Provide Bank Details: This option allows you to set your Bank Details such as the A/C number, Bank Name, IFSC code, BSR etc.