Perpetual vs Periodic Inventory System

Perpetual inventory system and periodic inventory systems are the two systems of keeping records of inventory.

In perpetual inventory system, merchandise inventory and cost of goods sold are updated continuously on each sale and purchase transaction. Some other transactions may also require an update to inventory account for example, sale/purchase return, purchase discounts etc. Purchases are directly debited to inventory account whereas for each sale two journal entries are made: one to record sale value of inventory and other to record cost of goods sold. Purchases account is not used in perpetual inventory system.

In periodic inventory system, merchandise inventory and cost of goods sold are not updated continuously. Instead purchases are recorded in Purchases account and each sale transaction is recorded via a single journal entry. Thus cost of goods sold account does not exist during the accounting period. It is determined at the end of accounting period via a closing entry.

Differences Between Perpetual and Periodic System

Following are the main differences between perpetual and periodic inventory systems:

  • Inventory Account and Cost of Goods Sold Account are used in both systems but they are updated continuously during the period in perpetual inventory system whereas in periodic inventory system they are updated only at the end of the period.
  • Purchases Account and Purchase Returns and Allowances Account are only used in periodic inventory system and are updated continuously. In perpetual inventory system purchases are directly debited to inventory account and purchase returns are directly credited to inventory account.
  • Sale Transaction is recorded via two journal entries in perpetual system. One of them records the sale value of inventory whereas the other records cost of goods sold. In periodic inventory system, only one entry is made.
  • Closing Entries are only required in periodic inventory system to update inventory and cost of goods sold. Perpetual inventory system does not require closing entries for inventory account.

Written by Irfanullah Jan