FIFO (first in, first out) is an inventory costing method where the oldest stock is assumed to be sold or used first. In Peasy, FIFO is the oldest-cost-first model used for lot-aware costing and inventory valuation.
How It Works in Peasy
- When Peasy has a complete batch cost, it records the cost per unit for that lot — no blended average
- Shopify orders can apply FIFO automatically: enable Auto-assign lot IDs in your Shopify connection settings and Peasy picks the oldest available lot first, splitting across lots when one runs short
- Regular sales orders don't auto-assign lots — you choose the lot on each line yourself. When the chosen lot has a recorded cost, that cost flows into COGS, so choosing the oldest costed lot gives you true first-in-first-out costing
- When a line has no usable lot cost, Peasy uses the current template COGS for made products or the current Items to buy price for bought products
- Inventory History records the cost captured at each transaction, so you can audit which lot's cost was applied
Why It Matters
FIFO gives you an accurate, consistent way to value inventory and calculate margins, because each lot keeps the real cost it was received at instead of a standard or blended number. For Shopify orders you can let Peasy apply oldest-first automatically; for other orders you stay in control of which lot — and therefore which cost — each line uses.