Taxation and room rentals in Switzerland: How to declare your rental income in 2026

Faced with the housing shortage affecting many Swiss cities, taking in a tenant has become an essential solution. At Roomlala, we see every day how this practice builds social ties while offering a welcome source of supplemental income. However, when it comes to the taxation of room rentals in Switzerland, many hosts hesitate, fearing administrative complexity. Rest assured: renting out a part of your primary residence is 100% legal and even encouraged by the authorities, provided you demonstrate tax transparency.

In this year 2026, the Swiss tax landscape is going through a fascinating transition period. Between old rules still in force and recently passed reforms, it is crucial to clearly understand your obligations. How do you successfully file your 2026 rental income tax return? What is the impact on your rental value? What deductions are authorized by the Federal Tax Administration? We guide you step-by-step so you can rent out your room with peace of mind.

Read also: Student housing in Flanders: What you need to know about the student lease for the 2026 school year, Start of the 2026 academic year in Italy: The advantages of Canone Concordato for renting out your room and Regulation of Short-Term Rentals: What is Changing for Students in Spain for the Start of the 2026 Academic Year

Understanding the legal and tax framework for homestays in 2026

Welcoming a student or young professional into an unused room in your house or apartment is not just a gesture of solidarity, it is also an activity governed by law. The legislation on renting a room in CH is very clear on this: any income generated by the rental of a property, even partial, constitutes taxable income. At Roomlala, we make it a point of honor to support you in understanding these rules to ensure a smooth experience.

In Switzerland, the basic principle of housing taxation is based on contributory capacity. If you receive rent every month, it increases your total income. It is therefore mandatory to declare these amounts to your canton's tax administration. Not doing so would expose you to unnecessary tax adjustments, especially since the authorized deductions often make the operation very advantageous.

It is also important to remember that renting a furnished room as a homestay benefits from great contractual flexibility. You remain in control of your home. However, for tax purposes, the Federal Tax Administration (FTA) does not make a fundamental distinction between a large apartment rented to a third party and a room rented in your own home: income must be declared accurately.

To illustrate this, let's take a frequent use case on our platform: you decide to rent a 15 m² room to a student at the University of Lausanne for 800 CHF per month, including utilities. Over a full year, this represents a gross income of 9,600 CHF. This is the exact amount that will have to appear in the section dedicated to real estate income in your 2026 tax return.

The 2026 rental income return: an obligation of transparency

Filling out your tax return can sometimes seem tedious, but cantonal forms have been greatly simplified in recent years. The 2026 rental income declaration is generally done in the section reserved for real estate investment returns. You must indicate the total amount of rent received during the past calendar year.

It is crucial to differentiate the net rent from utilities (water, electricity, internet). If you rent "all utilities included," as is often the case for a homestay, a portion of what you receive is used to cover the tenant's actual consumption costs. Depending on the canton, you may be able to deduct these incidental expenses from the gross taxable income, provided you can justify them or apply a recognized flat rate.

At Roomlala, we advise you to keep a small, accurate register of your payments. Keep the rental agreements generated on our platform as well as proof of bank transfers. This transparency is your best ally in the event of questions from cantonal tax authorities.

Finally, do not forget that this reporting obligation applies from the very first franc received. There is no "tolerance threshold" or exemption for small amounts in Switzerland. Rigor is required, but as we will see, it comes with very interesting rights to deductions.

Swiss rental value: what is changing (and what remains) in 2026

The Swiss rental value is arguably the most debated tax concept in the country. As a reminder, this is a fictitious income that owner-occupiers must add to their taxable income. The idea is to create tax equity between tenants (who cannot deduct their rent) and owners (who can deduct their mortgage interest and maintenance costs).

But what happens when you rent out part of this primary residence? This is where the system requires special attention to avoid any tax injustice. In 2026, adjustment rules are of capital importance for Roomlala hosts.

The reform calendar: no panic before 2029

You have likely heard of the historic September 2025 vote approving the abolition of the rental value. This is excellent news for owners, but pay attention to the timeline! The Federal Council has set the entry into force of this major reform for January 1, 2029. Consequently, the current tax system remains fully applicable in 2026, 2027, and 2028.

Therefore, you must not anticipate the end of the rental value in your current declaration. You must continue to declare it. The good news is that during this transitional period until the end of 2028, all benefits related to deductions (notably the interest on your mortgage debt) are fully maintained. This is therefore the ideal time to optimize your taxes while hosting a tenant.

We want to reassure our community: this transition period has been designed to give you time to adapt. At Roomlala, we follow these legal developments closely to provide you with information that is always up-to-date and secure.

Avoiding double taxation: the pro-rata adjustment

This is the question all owners ask us: "If I declare the room rent, and I also declare the rental value of my entire house, won't I be paying taxes twice on this same room?" The answer is no; the tax administration has provided a mechanism to avoid this double taxation.

Since the actual rent of the room is already taxed, you have the right to adjust or reduce the overall rental value of your property in proportion to the surface area rented. This pro-rata calculation is essential to optimize your declaration.

Let's take a concrete example: you own a 100 m² house with an annual rental value set at 15,000 CHF. You decide to rent a 20 m² room (i.e., 20% of the total surface area) on Roomlala. You will declare the rent received for this room, but in return, you will be able to reduce your rental value by 20%. You will therefore only declare 12,000 CHF in rental value.

Be careful, however, with cantonal specifics: some cantons require you to fill out a specific appendix to justify this calculation, while others integrate a dedicated box in their tax software. Check with your local tax office to find out the exact procedure to follow.

Authorized tax deductions: optimize your 2026 declaration

While renting a room generates taxable income, it also gives you the right to significant tax deductions. The Federal Tax Administration recognizes that maintaining a property for rental generates costs. In 2026, these deductions remain a powerful lever to reduce your overall tax burden.

It is fundamental to understand how to articulate these deductions with your rental income and your residual rental value. You generally have a choice between two methods: the deduction of actual expenses or the application of a flat-rate deduction.

Maintenance costs: actual or flat-rate?

As a landlord, even for just a single room, you can deduct the maintenance costs of your home. The flat-rate method is often the simplest: it allows you to deduct a percentage (generally 10% to 20% depending on the age of the building) of the rental value and/or the rental income, without having to provide supporting documents.

However, if you have carried out major work to accommodate your tenant, the deduction of actual expenses will be much more advantageous. Work that maintains value (painting, replacing a window, repairing plumbing) is considered deductible. Value-added work (adding a luxury bathroom that didn't exist before) is generally not.

Use case example: Before listing your room on Roomlala, you hired a tradesperson to repaint the walls and change the flooring, for a total of 3,500 CHF. If this amount exceeds the 10% or 20% flat rate to which you are entitled, it is in your best interest to opt for the deduction of actual expenses that year by attaching the invoices to your declaration.

We recommend that you do a simulation every year. The choice between actual expenses and flat rate is not permanent; you can opt for one or the other at each new tax return based on expenses actually incurred during the calendar year.

Mortgage interest deduction maintained

As mentioned previously in the reform calendar, mortgage interest remains fully deductible from taxable income until the end of the transition period, i.e., until December 31, 2028. This is a crucial piece of information for your 2026 financial planning.

The additional income generated by renting your room on Roomlala can thus be partially or totally offset by the deduction of this interest, as well as by maintenance costs. In many cases, the actual tax impact of renting a room turns out to be minimal compared to the net financial benefit you receive from it.

It is therefore strategically very relevant to rent a room in your primary residence during this period. You maximize the use of your property while taking full advantage of the current tax ecosystem before the big shift in 2029.

Cantonal specifics and best practices for renting with peace of mind

Switzerland is a federalist country, and taxation is no exception to the rule. While the general framework described above is set by the Confederation (direct federal tax), the exact calculation of the rental value, tax rates, and the exact percentages of flat-rate deductions vary considerably from one canton to another.

For example, the tax authorities of the cantons of Vaud, Geneva, or Zurich do not have exactly the same property assessment scales. It is therefore essential to emphasize these cantonal specificities: what is true in Lausanne is not necessarily true to the exact franc in Winterthur.

To rent with peace of mind with Roomlala, here is a list of best practices to adopt in 2026:

• Consult your canton's guidelines: Visit your cantonal tax administration website to download the 2026 explanatory notice regarding housing taxation.
• Formalize the rental: Use Roomlala's messaging and booking tools to keep a clear written record of rental dates and amounts received.
• Separate utilities: If possible, clearly stipulate in your communications the portion of the rent that corresponds to utilities (heating, electricity), as some cantons allow you to deduct them differently.
• Anticipate the pro-rata: Measure the surface area of the rented room precisely in relation to the total living area of your home to easily calculate the reduction of your rental value.

In conclusion, taxation should not be an obstacle to your desire to host a tenant. The legal framework in Switzerland in 2026 is designed to be fair and to encourage the optimization of living space. At Roomlala, we are proud to offer you a secure platform that facilitates these human and financial exchanges. By properly declaring your income and applying the deductions to which you are entitled, you will make renting your room an experience as enriching on a personal level as it is on a financial one.