"Best by" vs. "use by" vs. "sell by": what food date labels actually mean

You reach into the fridge, find a yogurt with a date that passed two days ago, and hesitate. Is it bad? The answer depends on which date it is — and, increasingly, on which state you are in — because the words on the package mean different things, and most of them are about quality, not safety.

If you remember one thing: except for infant formula, federal law does not require date labels on food. On most foods, the printed date is the manufacturer’s estimate of peak quality, not a safety deadline. “Best by” and “use by” are usually quality dates; “sell by” is a date for the store — though California changed the rules in 2026.

Most food dates are not required by federal law

Here is the fact that surprises most people: for most foods, the federal government does not require a date label at all. The USDA’s Food Safety and Inspection Service is direct about it — except for infant formula, product dating is not required by federal regulations.

That means the date on your cereal, bread, or canned goods is there because the manufacturer chose to put it there, usually as a quality guide. It is not a federal safety mandate.

What each phrase means

The phrases are not interchangeable. Here is the plain reading:

• “Best if Used By” / “Best By” — a quality date. It tells you when the product will be at its best flavor or quality. It is not a safety date.
• “Use By” — the last date recommended for the product at peak quality, set by the manufacturer. For most foods, still a quality date. (Infant formula is the exception, and California now treats “USE by” as a safety date — see below.)
• “Sell By” — a date for the retailer, telling the store how long to display the product for inventory management. It is not a safety date for you. (California now bars consumer-facing “sell by” labels on covered foods — see below.)
• “Freeze By” — when to freeze the product to maintain quality.

USDA’s Food Safety and Inspection Service recommends the “Best if Used By” phrase because it is the one consumers most clearly understand as a quality date.

The one real exception: infant formula

There is a federal requirement that matters: infant formula must carry a “use by” date, under 21 CFR 107.20. Unlike the quality dates on other foods, formula should not be used after that date. If you are feeding an infant, treat the formula date as a hard limit, not a suggestion.

California changed the rules in 2026

One state has moved beyond the voluntary federal approach. California’s AB 660 (codified at Cal. Food & Agric. Code § 82001) took effect July 1, 2026 for covered food manufactured on or after that date. It does three things:

• Requires the words “BEST if Used by” (or “BEST if Used or Frozen by”) for a quality date.
• Requires “USE by” (or “USE by or Freeze by”) for a safety date — so in California, “USE by” signals safety, not just quality.
• Bars consumer-facing “sell by” labels on covered foods (coded sell-by for retailer inventory is still allowed).

The law does not require a date label; it controls the words used when one is displayed. Exempt: infant formula, eggs, and beer or other malt beverages. Outside California, the voluntary federal reading above still applies. This matters for a California shopper: a “USE by” date there means safety, and a “sell by” date you might see elsewhere should not be on consumer-facing packaging in the state.

Is it safe to eat after the date?

Often yes — but “often” is not “always,” and the reason is that the dates are generally about quality, not safety. A product past its “best by” date may simply be less fresh. Whether it is still safe depends on the food, how it was stored, and whether it is a product where safety matters.

So the honest answer is conditional: use the date as a quality guide, not a safety guarantee, and follow food-safety basics. If food looks or smells spoiled, or has been left out, throw it out regardless of the date. Infant formula — and, in California, a “USE by” date — is where the date is a firm signal.

Why the confusion matters

Different products use different phrases because most labeling is voluntary and there is no single federal rule governing the wording on most foods. State laws also vary, and California now imposes specific wording.

That inconsistency has a cost. USDA and FDA have pointed to date-label confusion as a driver of household food waste: people throw out food that is still fine because they read a quality date as a safety deadline. That is part of why clearer wording — “Best if Used By” — is being encouraged.

Where to get official information

• USDA Food Safety and Inspection Service (FSIS) — the authority on food product dating and safe handling: fsis.usda.gov.
• FoodSafety.gov — the federal gateway to food-safety guidance from USDA, FDA, and CDC.
• California Department of Food and Agriculture (CDFA) — guidance on the AB 660 date-label rules: cdfa.ca.gov.
• The network’s health explainers collect these, alongside The expiration date is a potency guarantee, not a safety date, The Drug Facts panel explained, and How to read the Nutrition Facts label.

If a specific product’s safety is in question, the answer lives with USDA/FDA guidance and food-safety basics — not in a general explainer.

The bottom line

Most food date labels are not required by federal law and are quality dates, not safety deadlines: “best by” and “use by” tell you when food is at its best, and “sell by” is for the store. Infant formula is the federal exception — it carries a required “use by” date and should not be used after it. California has gone further since July 2026, using “USE by” for safety and barring consumer-facing “sell by.” Use dates as a quality guide, follow food-safety basics, and when in doubt, throw it out.

Vitals is the health site of the Omni Mundi Compendium network. The network’s explainers on drug labeling and food policy help you read what a label does — and does not — promise.

This article is general information about food date labels in the United States, not medical or food-safety advice, and not official guidance. Date-label rules and state laws can change. For food-safety questions, follow current USDA and FDA guidance. It is AI-written and independently AI-reviewed before publication; the review standard and this article’s findings are recorded in the network’s editorial review log.