Siblings Buying Something Together: Money and Ownership
By Erik Nilsen · Kroni6 min read
When two siblings want to pool their savings, agree on four things before anyone spends a dollar: how much each child puts in, who gets to use the item and when, what happens if one of them changes their mind before the purchase, and what each child's balance looks like afterward. Write it all on one sheet of paper. Set aside a quiet moment for the agreement so you have a shared reference if disagreements come up later.
You're not drawing up a contract. You're making three things visible: pooling money is voluntary, each child still owns their own money until the purchase, and the adults keep track.
First: it's voluntary, and it's only for extras
A sibling purchase should only cover things the kids want for themselves. Clothes, shoes, school supplies, dentist visits and other necessary expenses are the adults' job. They don't belong in the agreement.
Talk to each child separately before you all sit down together. A younger sibling might say yes just because an older one wants it. Ask plainly: "Do you want this yourself, or is it mostly because she asked?" Saying no is completely fine.
Step 1: Write down each child's share
Each child has their own savings, and that should stay clear. Write down:
- What the item costs (a fixed price, or a maximum).
- How much each child puts in, in dollars.
- Whether the share still needs to be saved up or already exists.
- Which adult keeps track.
The shares don't have to be equal. An older child may have more money and put in more. That's fine, but then either the use rules should reflect it, or you agree clearly that the item is shared equally no matter what. Either approach can work as long as both children understand and accept it. For more on handling different amounts between siblings, see Fair Allowance for Siblings: How to Avoid the Fights.
Step 2: Agree on use before the item arrives
This is where most arguments start, so be specific:
- Where does it live? In a shared room, or does it move between bedrooms?
- Who uses it when? For example, alternating days, or first come, first served with a time limit.
- Can friends use it? And do both siblings need to agree?
- What if it breaks? Who decides what happened, and does anyone pay for repairs?
- What happens in a few years? When one child stops using it, it can be sold, given away or passed to the other.
Keep the use rules separate from the money math. Paying 60 percent doesn't automatically mean getting 60 percent of the time. You decide that in the agreement, not with a calculator.
Step 3: Build in a way out before the purchase
Kids change their minds. Maybe the younger one suddenly wants to save for a bike instead. Decide ahead of time:
- Until the purchase, either child can back out. They keep all of their own money.
- What does the other child do then? Keep saving alone, pick something cheaper, or wait.
- A final check the day before buying. Ask both again. From then on, yes means yes.
- After the purchase, the item belongs to both under the use rules, and the money is spent.
Having a way out makes it safer to say yes in the first place, because nobody feels locked in.
Step 4: Update each balance on purchase day
When you buy the item, an adult pays with real money: cash, card or a mobile payment app. Afterward, subtract each child's share from their own balance. Check the numbers together: "You had $82, you put in $70, so now you have $12 left."
It helps to do this with both kids present, but look at one balance at a time. That makes it easy to see that nobody paid for the other.
Filled-in example: Ida and Jonas buy a building set
Fictional example. The amounts are illustrations only, not recommended sums.
Ida (11) and Jonas (8) want to buy a large building set for $120.
| Item | Agreement |
|---|---|
| Item and price | Building set, max $120 |
| Ida's share | $70 (has $82 saved) |
| Jonas's share | $50 (has $30, saves $20 more over about five weeks) |
| Necessary expenses included? | No. Own savings only |
| Tracked by | Dad |
| Where does it live? | Living room shelf, not in anyone's bedroom |
| Use | Build together on weekends. Weekdays: take turns every other day |
| Friends | Both must agree |
| Lost or broken pieces | Whoever lost the piece helps look for it. Nobody pays |
| If someone backs out before buying | Keeps their whole share. The other decides whether to keep saving |
| Final check | The Friday before the purchase |
| Selling later | The actual sale proceeds are split in a 7:5 ratio if both agree to sell |
On purchase day: Ida's balance goes from $82 to $12. Jonas's balance goes from $50 to $0. The building set goes on the living room shelf.
Template: sibling purchase agreement (copy and fill in)
| Item | Child 1 | Child 2 |
|---|---|---|
| Name | ||
| Saved so far | ||
| Putting in | ||
| Still needs to save (amount and rough time) | ||
| Said yes alone with an adult? |
| Shared agreement | Answer |
|---|---|
| What we're buying, and max price | |
| Necessary expenses not included (check) | |
| Adult who keeps track | |
| Where the item will live | |
| Who uses it when | |
| Friends and lending | |
| If it breaks | |
| If someone backs out before buying | |
| Date of final check | |
| If the item is sold or given away later | |
| Signature or drawing from both children |
How this can look in Kroni
The example numbers show money before it is set aside in app savings goals. If you have already moved a child's share into a goal, you can move it back to the available balance before recording the purchase once. That transfer is not new income, and the same amount must not be deducted from both the goal and the balance.
In Kroni, each child has their own balance and their own savings goals, which suits a shared purchase well. Each child can have a goal for their own share, for example "Building set with Jonas: my part $70." When kids complete paid chores, their balance grows (after adult approval where you've chosen to require it), and money can be moved from the balance into the goal. Kroni has no shared account and doesn't move money between siblings. You pay for the item outside the app, then update each child's balance. A child can have several savings goals at once, so the shared purchase doesn't have to push aside anything else they're saving for.
If your kids need help understanding what the numbers mean, Balance Explained for Kids: Goals, Mastery and Money is a good place to start.
Get started this week
- Talk to each child alone: do they really want this?
- Fill in the template together, ideally at the kitchen table.
- Set up each child's share as a separate savings goal or a separate line on paper.
- Pick a date for the final check.
- Put the sheet up where the item will live, so the use rules are easy to find.
Frequently asked questions
- Do siblings have to pay equal amounts to own something together?
- No. Shares can differ, for example if one child has saved more. What matters is that both understand and accept the split, and that you decide separately whether use is shared equally.
- What if one child regrets it after the item is bought?
- Then the money is spent, and the item is shared under the use rules you agreed on. That's why a final check before buying helps: either child can back out then and keep their whole share.
- Can Kroni transfer money from one child to another?
- No. Each child has their own virtual balance and savings goals, which can show their agreed share. Kroni has no shared account and doesn't move money. An adult pays for the item outside the app, and then you update each child's balance.
