What Can Your Rent Increase By, and How Often?

Last updated September 21, 2026

Short answer: It depends on which rules apply to your home. Free rent rises only as the lease allows, usually yearly by the net price index. Cost-based rent can rise with building costs, and "value of the tenancy" rent at most every two years, though a yearly index clause is possible in both. You usually have 6 weeks to object.

One day a letter arrives from your landlord: the rent is going up by 450 kr. a month from 1 April. Is that legal? It depends on when the building was first used, how many flats it has, and which municipality it's in. The Danish Rent Act (lejeloven) doesn't have one set of rules for rent. It has three – plus a special rule for smaller buildings.

Which rules apply to your home?

Your home and rule set	How the rent can rise
Free rent (fri leje, section 54 of the Rent Act): first used after 1991	Only as the lease allows – usually net price index
Cost-based rent (omkostningsbestemt leje, sections 19-31): 7+ flats on 1 Jan 1995, regulated municipality	When operating costs rise (section 23), by net price index in 2-year periods (section 26) – or once a year by net price index if the lease says so (section 53(2))
The small-building rule (section 32): 6 or fewer flats on 1 Jan 1995, regulated municipality	Up to the value of the tenancy, but with a ceiling (see below)
The value of the tenancy (sections 42-45): unregulated municipality	Up to the level of comparable homes, at most every second year

Free rent can also apply to flats that were used only for business before 1992 and to newly converted attic flats, but then the lease must say so. Your municipality can tell you whether it is "regulated" (reguleret). You can look up the building's construction year in the BBR register at boligejer.dk.

Free rent: only what the lease says

If you have free rent, your landlord can only raise the rent if the lease allows it. Usually the lease links the rent to Statistics Denmark's net price index (nettoprisindeks, NPI), and the increase can then be made simply by written notice to you (section 54(3)). According to the Copenhagen rent tribunals, leases signed after 1 July 2015 can't include stepped rent (trappeleje), meaning fixed, pre-agreed increases – only NPI adjustment.

A worked example with made-up figures: you pay 10,000 kr. a month, and the index has risen from 115.0 to 117.3 since the last adjustment. That's a 2% increase, so the new rent is 10,200 kr.

Cost-based rent: costs set the ceiling

In older rental buildings with 7 or more flats in regulated municipalities, the rent may only cover the building's necessary operating costs – taxes, insurance, administration, maintenance and the like – plus a limited return (section 19). If costs rise, the landlord can demand a rent increase to cover the difference (section 23). The demand must be in writing and include the old and new budget, the calculation and information about your right to object. Otherwise it is invalid (section 29). As a rule, the increase takes effect from the 1st of the month 3 months after the demand.

If at least a quarter of the affected tenants object in writing within 6 weeks of receiving the demand, the landlord must bring the case before huslejenævnet (the local rent tribunal) within a further 6 weeks to maintain the increase. Buildings with a tenants' board follow a slightly different procedure. You can also always ask the rent tribunal yourself to assess whether the landlord is charging more than allowed (section 38).

Alternatively, the landlord can choose to adjust the rent by the net price index for 2-year periods (section 26). This only applies to the part of the rent that covers operating costs other than taxes and duties, and when the 2 years are up, the landlord must recalculate the rent from the budget – and lower it if it has become higher than allowed.

If your lease says the rent is adjusted by the net price index, the landlord can also adjust it once a year by written notice (section 53(2)). This also applies to thoroughly modernised flats (section 19(2)). If you think the rent then exceeds what's allowed, you can ask the rent tribunal to assess it (section 38).

The value of the tenancy: smaller buildings and unregulated municipalities

If the rent is substantially lower than the value of the tenancy (det lejedes værdi) – what comparable homes in the area cost, judged by location, size, quality, fittings and state of repair – the landlord can demand an increase to a reasonable level (section 42). The increase can take effect at the earliest 2 years after the tenancy began, or 2 years after the last increase of this type, and requires 3 months' notice (sections 42(5) and 44).

The notice must be in writing and state the amount, the reason and your right to object. If you don't accept it, you must object in writing within 6 weeks of receiving it. The landlord must then bring the case before the rent tribunal within a further 6 weeks to maintain the demand (section 44(3)). Until the tribunal has decided, the landlord may charge a provisional increase of no more than 15 kr. per m² per year.

In smaller buildings in regulated municipalities, the rent also may not be substantially higher than the rent for comparable cost-based tenancies (section 32). Here too, the lease can say that the rent is adjusted by the net price index once a year (section 53(2)).

Rising property taxes follow their own rule

If the property taxes go up, the landlord can pass the increase on through a rent increase with 3 months' notice – even if your lease can't be terminated for a fixed period (section 46). If the demand is made within 5 months of the tax being imposed, it can take effect from that date. The same applies to new or higher public charges for things like water and waste collection (section 47). The demand must be in writing, include a calculation and state your right to object, and the objection deadline is again 6 weeks. If the taxes fall, the landlord must lower the rent (section 48). If you have free rent, the Copenhagen rent tribunals say this requires the lease to reserve the right to pass on tax and duty increases.

Is there a cap on how much the rent can rise?

Not a general one. The temporary cap of 4% a year on NPI increases, which the Danish Parliament passed in 2022 for two years, no longer applies. The limits are those of the rule set that covers your home – and your lease.

What to do when you receive a notice

Work out which rule set your home falls under, and read the lease's special terms on rent adjustment.
Check the formal requirements: is the notice in writing, does it state the amount and the calculation, and are you told about your right to object? If anything is missing, the notice may be invalid.
Write down the date the letter arrived. The objection deadline is usually 6 weeks.
If you disagree, send a written objection stating which points you don't accept, and keep a copy.
Get advice early. Lejernes LO (LLO), the national tenants' union, advises its members – membership starts at 700 kr. per half-year at LLO Hovedstaden. The rent tribunal decides cases but doesn't give advice.

If you think your current rent is already too high, read Is your rent too high? – there, the deadline is typically 1 year. And if you're looking at a new home on LejLet.nu, ask the landlord through the messaging feature how the rent is adjusted before you sign.