You drag out the grill for the season, hook up the tank, and head to the refill station — only to have the attendant hand it back unfilled. "This tank is expired." It's a frustrating surprise, but it's also a safety system working correctly. Here's what the expiration date on your propane cylinder actually means, how to find it, and what your options are.

Why Propane Tanks Have an Expiration Date

Propane cylinders are pressurized steel vessels. Over time, steel can corrode, weaken, and develop micro-fractures. The U.S. Department of Transportation (DOT) mandates that portable propane cylinders — including the standard 20-lb grill tank — must be inspected and recertified after 12 years from the date of manufacture. After recertification, they get an additional 5-year service life, with re-recertification required every 5 years after that.

Refill stations are required by law not to fill an expired tank. Exchange programs like Blue Rhino will take expired tanks as part of a swap — and this is actually one of the legitimate reasons to use an exchange when your tank is aging out.

How to Read the Date Stamp on Your Tank

The manufacture date is stamped into the metal collar at the top of the cylinder — the thick ring around the valve. Look for a format like 06 14 or 06/14, which means June 2014. Some tanks use a letter for the month (A = January, B = February, etc.) followed by the two-digit year.

If you see a letter-and-date stamp elsewhere on the collar — something like E★26 — that's a recertification mark. The star (★) is the federally recognized symbol for a qualified inspector, followed by the year the recertification was performed. A recertified tank is valid for 5 years from that date.

Here's what to look for at a glance:

What Happens at 12 Years?

At 12 years from manufacture, your tank enters expired status. This doesn't mean it's immediately dangerous — it means it hasn't been inspected in 12 years and legally can't be refilled until it is. The tank may be perfectly fine; the rule is precautionary, not a verdict on the actual condition of your specific cylinder.

Refill attendants check the date stamp before filling. If your tank is expired, they will decline to fill it. This is non-negotiable at legitimate stations — it's a federal regulation, not a store policy.

How Does Recertification Work?

Recertification is performed by a DOT-qualified inspector. The process involves a visual inspection of the tank body, collar, foot ring, and valve for corrosion, dents, gouges, and damage. If the tank passes, the inspector stamps the collar with their identifier and the year. The tank is then good for another 5 years.

Recertification typically costs $5–$15 at a propane dealer or U-Haul location that offers the service. Not every refill station offers recertification — call ahead before making a trip.

When Recertification Isn't Worth It

Recertification makes sense for a tank in good physical condition. It doesn't make sense if:

• The tank has visible rust deeper than surface oxidation
• The collar or foot ring is badly dented or deformed
• The valve is damaged or leaks
• The tank is more than 20+ years old and has already been recertified once

In these cases, replacing the tank outright is the better call. A new 20-lb cylinder costs $30–$50 at hardware stores. You can also use a propane exchange — hand over the expired tank and walk out with a newer one as part of the swap.

The Exchange Workaround

Propane exchange programs (Blue Rhino, AmeriGas) accept expired tanks as part of a swap. You hand over your expired cylinder, pay the exchange fee, and receive a current-date tank in return. You don't get a refund for whatever propane might have remained in your old tank, but you do get a fresh, in-date cylinder without paying separately for a new one.

This is the fastest and most convenient way to deal with an expired tank — though you'll pay more per gallon of propane than you would at a refill station. Once you have a new in-date tank from an exchange, switch back to refills to save money going forward.

Large Tanks: Different Rules

The 12-year rule applies to portable DOT cylinders — the kind you carry to a refill station. Large stationary tanks (100 gallons and up) that sit on your property operate under different regulations. These are typically owned or leased from your propane supplier, and they handle inspection and recertification as part of service. You don't need to manage the expiration date on a leased tank — your supplier does.

Quick Reference: Cylinder Expiration

Find a Refill Station Near You

Once your tank is in-date — whether recertified or replaced — find a refill station near you to get the best value on propane. Browse our directory by city: Houston, Dallas, San Antonio, Austin, Fort Worth, Arlington, Corpus Christi, and El Paso. New Mexico residents can browse Albuquerque, Santa Fe, and Las Cruces. Or use the interactive map to find the closest location.

The Bottom Line

Check the date stamp on the collar of every propane cylinder you own. If it's been 12 years since manufacture — or 5 years since the last recertification mark — your tank is expired and won't be refilled. Options are: get it recertified for $5–$15 if it's in good shape, use it for an exchange to get a newer tank, or buy a replacement cylinder. Set a reminder so you're not caught off guard when grilling season starts.