A larger private payment is due only once a year. In the other months the need for money therefore appears lower than it is over the year. For your personal housing cost planning you can convert such dates into monthly savings amounts. This concerns your own budget, not the legal reserve of an owners' association or any specific bank requirement.
First collect the actual payments
Use existing statements and agreements as a starting point. Note the amount, due date and the period to which the payment relates. If the next amount cannot yet be determined reliably, mark the entry as an estimate rather than treating the last payment as a certain repetition.
The Austrian Finanznavi generally explains the comparison of income and various types of expenses. [BUDGET] We use this general budgeting method here as an editorial aid also for people in Germany. No German legal or tax rules are derived from this.
Distinguish between savings amount and account balance
If you divide an annual amount by twelve you initially get a calculated monthly allocation. That does not mean the money is actually available. Check whether the corresponding sum has actually been set aside and when the next payment is due.
If your planning begins in the middle of the year, the time until the due date is decisive. An amount that is appropriate over twelve months can be too little if you only start saving shortly before the next bill. Therefore note the starting balance and the remaining months.
Example: The same annual payment, two different starting situations
For a fictional private payment of 1.200 euro per year the distribution over twelve months results in 100 euro monthly. If six months remain until the next due date and no funds have yet been set aside, the calculation instead yields 200 euro per remaining month.
This is not a recommendation for a specific spending level. It merely shows why a monthly allocation without an existing opening balance and next payment date can conceal a gap. Whether the payment actually falls due in your case is checked against your own documents.
Avoid double reserves
If you earmark money for a specific bill it should not at the same time appear as freely available spending money in the same overview. Conversely, the subsequent debit must not be added again as a new annual charge if you are using the amount you have already saved.
A simple system can be sufficient: purpose, existing balance, monthly allocation, next date. You decide the technical storage and the appropriate account structure based on your situation; the article does not recommend any financial product.
After the actual payment compare the allocation and the result. If the amount or the frequency changes, adjust the next plan. The method does not guarantee complete financial protection, but it does make a well-known weakness visible: money that will be needed later is not free in today’s account balance simply because the bill has not yet arrived.