FIFO or LIFO - What's the Difference? Which is Better?

FIFO First-in, First-out Inventory Costing Explained
••• John McBride & Company Inc./Getty Images

Around the end of a business's fiscal (financial) year, auditors and accountants start to talk about "taking inventory" and "LIFO vs. FIFO." But what's the difference between these terms, and which one is better for my business? This article looks at inventory in general and FIFO and LIFO as the two most common methods to value inventory.

But first, we need to look at inventory, because FIFO and LIFO are ways of keeping track of inventory for cost of goods sold calculations.

Do I Have to Keep Track of Inventory?

Under the Tax Cuts and Jobs Act, effective in 2018, your small business with less than $25 million gross receipts can treat inventory as "non-incidental materials and supplies" (meaning that they are items bought for resale). You must also use an accounting method that clearly reflects income. In this case, you can use the cash method of accounting.

If you do keep inventory, the IRS requires you to use the accrual method of accounting.

Cash accounting and accrual accounting are different methods for determining when income and expenses are counted for financial accounting purposes.

How is Inventory Used for Cost of Goods Sold?

You must keep inventory so you can calculate the cost of the products you sell during the year. This calculation is called "cost of goods sold."

Cost of goods sold is calculated as:

  • Inventory at the beginning of the year
  • Plus the cost of purchases to inventory
  • Plus the cost of labor, materials and supplies, and other costs
  • Less inventory at the end of the year. 

The cost of beginning and ending inventory is an important factor in COGS. How inventory is valued plays a big part in the business tax situation. The greater the cost of goods sold, the less the company's profits - and the lower the company's taxes.

Inventory Valuation Methods Described

You must value your inventory at the beginning and end of the year. The valuation method you use must:

Since inventory is constantly coming into and going out of a company, it's difficult to keep track of the cost of individual items inventory, so generally accepted accounting standards allow businesses to use some general guidelines in valuing the cost of inventory.

Acceptable Methods for Valuing Inventory

Specific Identification. Some types of products can be valued individually and a specific value assigned. For example, antiques, collectibles, artwork, jewelry, and furs, can be appraised and a value assigned. The cost of these items is typically the cost to purchase, so the profit can easily be determined.

First-in, First-out (FIFO)Under FIFO, it's assumed that the inventory that is the oldest is being sold first. The FIFO method is the standard inventory method for most companies. FIFO gives a lower-cost inventory because of inflation; lower-cost items are usually older.

Last-in, First-out (LIFO).LIFO is a newer inventory cost valuation technique (accepted in the 1930s), which assumes that the newest inventory is sold first. LIFO gives a higher cost to inventory.

Which is Better - LIFO or FIFO?

First, remember this: Higher-cost inventory = lower taxes. Lower-cost inventory = higher taxes. To assess the relative value of LIFO and FIFO inventory cost, you need to look at the way your inventory costs are changing:

  • If your inventory costs are going up, or are likely to increase, LIFO costing may be better, because the higher cost items (the ones purchased or made last) are considered to be sold. This results in higher costs and lower profits.
  • If the opposite its true, and your inventory costs are going down, FIFO costing might be better. Since prices usually increase, most businesses prefer to use LIFO costing.
  • If you want a more accurate cost, FIFO is better, because it assumes that older less-costly items are most usually sold first.

The decision to use LIFO vs. FIFO is complicated, and each business situation is different. You must conform to IRS regulations and U.S. and international accounting standards. Get help from your tax professional before you decide on an inventory valuation method.

IRS Regulations and FIFO vs. LIFO

As you might guess, the IRS doesn't like LIFO valuation, because it usually results in lower profits (less taxable income). But the IRS does allow businesses to use LIFO accounting, requiring an application, on Form 970

The national accounting standards organization, the Financial Accounting Standards Board (FASB), in its Generally Accepted Accounting Procedures, allows both FIFO and LIFO accounting. The international accounting standards body (IFRS) doesn't allow LIFO to be used, so if your company has international locations, you probably won't be able to use it.

Restrictions on Changing Inventory Methods

If your business decides to change to LIFO accounting from FIFO accounting, you must file Form 970 with the IRS, and you will not be allowed to go back to FIFO accounting unless the IRS gives specific permission. 

Periodic vs Perpetual Inventory and LIFO or FIFO

Businesses use one of two ways to manage inventory - periodic and perpetual. Periodic inventory management is tracked manually, counting at the end of an accounting period. Perpetual inventory is for larger businesses using point-of-sale technology. 

Your business can use either LIFO or FIFO with either of these inventory management systems. 

Recordkeeping Issues and Inventory Accounting

LIFO inventory accounting increases record-keeping, because older inventory items may be kept on hand for several years, while under FIFO those older items are sold first, so recordkeeping requirements are less.

The decision to change inventory methods or to change back is complicated and has many tax and accounting implications. This article provides general information, not tax or legal advice. Talk to your CPA and tax advisor and get opinions on your specific business situation before you attempt to make a change.