Why make a coin bank instead of using a jar
A coin bank is a container designed to hold coins and make it harder to spend them without thinking. Unlike a loose jar, a bank with a slot or lock creates friction—you have to make a deliberate choice to withdraw money. This matters because coins accumulate fast and disappear faster. A bank keeps small change visible and separate from your everyday wallet, which means you're more likely to notice when you have enough to roll, deposit, or use for a specific purpose.
Making one yourself costs almost nothing and takes an hour or less. You control the opening size, the difficulty of withdrawal, and whether the bank is transparent (so you can see how much you've saved) or opaque (so the total is a surprise). A homemade bank also works better than a commercial one if you need to accommodate specific coin sizes or if you want a withdrawal method that suits your habits.
Key Takeaways
- A coin bank with a slot or lock slows down spending and makes you more aware of how much change you're holding.
- The simplest version uses a jar with a slot cut in the lid, a lock, or a cork that you remove to empty it.
- A plastic bottle bank takes five minutes and requires only a bottle, scissors, and tape to seal the opening.
- Transparent banks let you watch your savings grow; opaque ones create a surprise when you finally open them.
- Most homemade banks hold coins indefinitely without damage, but avoid metal containers that rust or lids that corrode.
The basic jar bank with a slot
Start with any glass or plastic jar with a lid—mason jars, pasta sauce jars, and peanut butter jars all work. The jar should be large enough to hold at least a few dollars' worth of coins without filling up in a week. Wash and dry it completely.
Cut a slot in the lid using a rotary tool, a drill with a small bit, or a utility knife. The slot should be wide enough for the coins you use most (usually a quarter, which is about 0.95 inches across). Make the slot no longer than 1.5 inches so coins don't jam or fall out sideways. Sand the edges smooth so they don't cut your fingers or damage coins.
Screw the lid back on. Test the slot by dropping in a few coins from different denominations. If a coin gets stuck, widen the slot slightly. Once it works, you're done—no glue, no sealing required. To empty the bank, unscrew the lid and pour the coins out, or drill a second small hole in the bottom and use a cork or rubber stopper to plug it until you're ready to withdraw.
The plastic bottle bank
A plastic bottle bank is the fastest option and works well for small daily change. Use a clean 20-ounce soda bottle, water bottle, or similar container. Avoid very thin plastic that crushes easily or very thick plastic that's hard to cut.
Cut a slot in the bottle about 1 inch from the top using scissors or a utility knife. Make the slot roughly 0.5 inches wide and 1.5 inches long—large enough for a quarter but not so large that coins spill out if you tip the bottle. Sand or file the edges smooth. If the cut edges are still sharp, wrap a small piece of duct tape around them on the inside.
To seal the bottle, use a hot glue gun to attach the original cap, or cut a piece of duct tape and cover the bottom of the bottle so coins can't fall out. When you're ready to empty it, cut along the bottom seam with a utility knife, pour the coins out, and tape the seam closed again. This method works for a few months before the tape weakens, but it's cheap to rebuild.
The locked bank with a key
If you want to make withdrawal harder, use a small lockbox or a jar with a padlock. A lockbox costs $5 to $15 and comes with a key. Drill or cut a slot in the top the same way you would for a regular jar bank. The lock goes on the lid or on a hasp attached to the box.
This version works best if you're saving for a specific goal and don't want to be tempted to open it. Keep the key somewhere you can find it but not somewhere you reach for automatically—a drawer in another room, or with someone else. The downside is that you can't quickly check your balance without unlocking it, and if you lose the key, you'll have to cut the lock or pry the box open.
The transparent bank to watch your progress
A clear glass or plastic container lets you see your coins accumulate, which reinforces the habit of saving. Use a clear plastic storage container, a glass vase, or a clear acrylic tube. Cut a slot in the lid or top the same way as a jar bank.
The advantage is psychological: watching coins pile up creates momentum and makes the savings feel real. The disadvantage is that you can see exactly how much you have, which might tempt you to spend it. Some people find this motivating; others find it stressful. If you want the visual feedback without the temptation, use a frosted or translucent container so you can see the coins but not count them at a glance.
Materials and tools you likely already have
| Bank Type | Container | Tools Needed | Time to Build |
|---|---|---|---|
| Jar with slot | Glass or plastic jar with lid | Drill, rotary tool, or utility knife; sandpaper | 10–15 minutes |
| Plastic bottle | 20-ounce plastic bottle | Scissors or utility knife; duct tape | 5 minutes |
| Locked box | Small lockbox or jar | Drill or utility knife; padlock and hasp (optional) | 10 minutes |
| Transparent bank | Clear plastic or glass container | Drill or utility knife; sandpaper | 10–15 minutes |
Most of these tools are in a basic household toolkit. If you don't have a drill, a utility knife works for plastic and thin metal. If you don't have sandpaper, a nail file or the rough side of a sponge smooths plastic edges. The only material you might need to buy is a padlock if you want a locked bank, and even that's optional.
What to do when your bank is full
When coins reach the top, you have three options: empty it into a coin counter or sorter, take it to a bank or credit union, or roll the coins yourself. A coin counter at a grocery store or arcade charges a small percentage (usually 5 to 10 percent) but takes the work out of sorting. A bank or credit union will count and deposit coins for free if you have an account there. Rolling coins yourself takes time but costs nothing—you'll need coin wrappers, which come in packs of 50 for a few dollars.
Before you empty the bank, decide what you'll do with the money. If you're saving for a specific goal, deposit it into a separate savings account so you don't spend it. If it's just loose change, you can use it for everyday purchases or add it to your regular cash spending. Either way, once the bank is empty, you can start filling it again.
Frequently Asked Questions
Can I use a metal container for a coin bank?
Metal containers work but have drawbacks. Steel rusts if moisture gets inside, and aluminum corrodes over time. If you use metal, drill the slot carefully to avoid sharp edges, and make sure the lid seals tightly so condensation doesn't build up. A painted metal box is better than bare metal because the paint slows rust.
What size slot should I cut for different coins?
A quarter is the largest U.S. coin at 0.95 inches across, so a slot 1 inch wide will accept all coins. If you want to accept only certain denominations (for example, quarters and dimes but not pennies), make the slot narrower—about 0.75 inches wide will take quarters and dimes but reject pennies. Test with actual coins before you finalize the slot size.
How do I make a bank that's hard to open by accident?
Use a padlock, a cork stopper in a drilled hole, or a screw-on cap instead of a slot. A slot is convenient but tempting; a locked or sealed bank requires deliberate effort to open. If you want something in between, use a small hinged door on the side with a simple latch, so you can open it but it doesn't fall open on its own.
Will coins get damaged or tarnished inside a plastic bank?
Coins won't be damaged by plastic. They may tarnish slightly over years if moisture gets inside, but this is cosmetic and doesn't affect their value. To prevent tarnish, make sure the bank is sealed tightly and stored in a dry place. Avoid metal containers that can rust and transfer rust stains to coins.
Can I make a bank that holds paper money too?
Yes, but it changes the design. Instead of a narrow slot for coins, cut a wider rectangular opening (about 1 inch by 3 inches) in the lid or side. You can fold bills and slide them through. If you want to separate coins and bills, use two containers or divide one container with a cardboard divider glued to the inside.