In short: Agree on an account model, split shared costs by income rather than strictly 50/50, save early and broadly for your child, and protect the family income with a larger emergency fund and suitable insurance cover.
Money works best in a family when it is arranged fairly and talked about openly. A few clear agreements head off most of the conflict.
Pick an account model: separate, joint, or the three-account setup (one joint account for all fixed costs, plus a personal account each for the rest).
Split shared expenses by income rather than strictly in half – whoever earns more carries a larger share. Many couples find that simply feels fairer.
Start saving for your child early: a small monthly amount, invested in a broadly diversified way. The biggest lever is usually not the sum but the time it has to grow.
Protect the family: a larger emergency fund and, if anyone depends on the income, a look at term life and disability cover. Plan it together in Kontoo.
What matters
A common stumbling block is splitting shared costs strictly in half when incomes are far apart – that puts a proportionally heavier load on the lower earner. Many people find splitting by income share fairer: if one partner nets 3,000 € and the other 2,000 € (5,000 € together), they carry roughly 60% and 40% of the joint costs. When saving for a child, time is the decisive factor: starting early with a broadly diversified investment lets compounding work for nearly two decades – though investment returns fluctuate and are not guaranteed. Protection often means a larger emergency fund than a single person needs (a commonly cited range is four to six months of expenses), and if children or a partner depend on the income, it is worth a look at term life and disability cover. In Germany, the state child benefit (Kindergeld) can cover part of the amount you set aside for the child. This is general education, not individual advice – the right products and amounts depend on your situation.
Example50 € a month over 18 years is 10,800 € paid in; at an assumed 6% annual return (compounded monthly, for illustration only – not guaranteed) it would grow to roughly 19,000 €. Of the roughly 19,000 € final value, about 8,200 € would be pure gain – nearly half, created by the long horizon and compounding alone.
Put your shared expenses into Kontoo and split them fairly by income automatically – all private on your own device.
In depth
When incomes are far apart
The pure income-based split has a catch many couples only notice years later: contributing the same percentage still leaves wildly different absolute amounts in each pocket. If one partner earns roughly 4,000 € net and the other 2,000 €, then on, say, 2,400 € of shared costs the higher earner keeps far more spending money after the 67/33 split. That is why some couples add a „floor“: each person first deducts a base amount for their own living costs, and only the rest is split by ratio — this noticeably protects the smaller income. It gets delicate during parental leave or part-time work for the child, because income drops while care work rises; if unpaid work is ignored, the person stepping back pays twice. The cleaner approach is to reset the ratio every year and deliberately compensate for reduced-earning phases, for instance through higher savings deposits into the caregiver’s account. What matters is not the perfect formula but that both feel the outcome is fair and talk about it openly.
Saving for the child — in whose name?
When investing for a child, people often focus only on returns and overlook the ownership question — yet that is what decides everything later. A securities account in the child’s name legally belongs to the child: at 18 they gain full access, and parents may not divert the money for their own purposes beforehand, because they only manage it on the child’s behalf. That can be intentional, but it can also become awkward when an 18-year-old suddenly controls 30,000 € alone. If parents instead save in their own name with a mental label „for the child“, they keep control but pay tax on the gains themselves, and a later transfer may count as a gift. Children also have their own annual saver’s tax allowance (around 1,000 € as of 2026) plus a basic allowance, so capital gains in a child’s account often stay tax-free — as long as the child has no significant income of their own. A common intermediate mistake is also investing large sums all at once instead of contributing over years; a small standing order smooths out price swings and makes the goal realistically reachable.
Protection: cover the right risk first
When it comes to insurance, many families reflexively buy an embellished children’s policy and overlook the biggest risk: the loss of the income everyone lives on. If a parent dies or is out of work for a long time, it is not a little money that is missing but half or all of the family’s livelihood — which is why term life and disability cover for the earners usually come before anything else. A common rule of thumb for the death benefit is roughly three to five times annual income (counted gross or net depending on the source), depending on remaining debt, number of children and existing assets; on 40,000 € that would be around 120,000–200,000 €. One nuance often forgotten: unmarried couples should insure crosswise — each person takes out the policy on the other’s life and is themselves the policyholder and premium payer, otherwise inheritance tax can fall on the payout (the allowance for unmarried partners is only 20,000 €). Contracts should also be reviewed after every major change — a birth, buying a home, a salary jump — because a sum that fit ten years ago may be too tight today. The pricey children’s accident or education policy, by contrast, is rarely what actually carries the family.
Checklist
Account model agreed together
Shared expenses split by income
Monthly amount for the child set up
Emergency fund and protection reviewed
Common myths
Myth: A fair split always means 50/50.
Reality: With unequal incomes, many find splitting by income share fairer than a strict half-and-half.
Myth: Saving for a child only pays off with large amounts.
Reality: Time is often what counts: a small amount invested early can beat a large amount invested late.
Frequently asked questions
Should we put everything into one joint account?
Not necessarily. In the three-account model, fixed costs run through a joint account while each partner keeps a personal account for their own spending. That gives you a clear overview and personal freedom at the same time. Which model fits depends on your situation.
How much should we save for our child?
Starting early and regularly matters more than the amount. Even a small monthly sum can grow meaningfully over 18 years – the long runway is the real lever.
