A year of inflation has brought back a question many landlords had almost forgotten: can I raise the rent while the lease is still running? Tenants ask the reverse — can the owner simply announce a new price from next month?
The short answer is the same for both sides: the rent changes only in the way the parties agreed. Below we explain what Bulgarian law says, what a workable indexation clause looks like, and how to reach an increase without a dispute — or an empty property.
What the law says
Leases are governed by the Obligations and Contracts Act (ЗЗД). The law provides no automatic inflation indexation of rent and no cap on increases for residential lets between private parties. So everything turns on the contract.
The core rule is Art. 20a ЗЗД: contracts have the force of law between the parties and can be changed only by mutual consent or on grounds provided by law. In practice:
- Fixed-term lease with no increase clause — the rent stays the same until the term ends. A one-sided "notice of new rent" does not bind the tenant.
- Fixed-term lease with an indexation clause — the increase happens under the rules in the clause, with no new signature needed.
- Open-ended lease — either party can end it by giving notice (Art. 238 ЗЗД), as a rule one month. So with an open-ended lease, proposing a new rent is in practice a negotiation: if the parties cannot agree, either can terminate.
One detail matters: if the term expires and the tenant stays on with the landlord's knowledge and without objection, the lease is treated as extended for an indefinite period (Art. 236 ЗЗД) — at the same rent. If you want a new price once the term ends, agree it before that point, not after.
An indexation clause that works
The calmest option for both sides is to write the increase in at signing. A good clause answers five questions:
- Linked to what? The clearest benchmark is the annual change in the consumer price index (CPI) published by Bulgaria's National Statistical Institute (NSI). The harmonised index (HICP) also works. Name exactly which index and which period — for example, "annual inflation for the month preceding the anniversary of the lease".
- When? Once a year, on the lease anniversary — not "as needed".
- With a cap and a floor? A cap (no more than a set percentage a year) protects the tenant if prices spike. A floor (the rent does not fall in a deflation) protects the landlord. Both are lawful if agreed.
- How is it notified? In writing — by email or message to an address named in the lease, with the calculation and the new amount, several weeks before the date.
- How is it rounded? To the euro cent.
An example using NSI's September inflation figure of 5.7% year on year (published 14 October 2026): on a rent of €700, indexation gives €739.90 a month. With a 5% cap in the lease, the new rent is €735.
A percentage is not compulsory. Some parties prefer a fixed step — for example "+€20 from the second year". It is predictable, but it does not track actual inflation.
If the lease has no clause
Then the route is an annex — a short supplementary agreement signed by both parties, stating the new rent and the date it applies from. A few practical points from our own work:
- Start the conversation early — at least a month or two before the anniversary or the end of the term, not with the last payment.
- Argue from data, not feeling. Official inflation and the rental market are different things. According to Eurostat, annual rent growth in Bulgaria slowed to 7.6% in September 2026 — we covered this in detail in our rental market report. Compare with current listings for similar homes in the same neighbourhood, too.
- Price in an empty month. One month without a tenant, plus preparation and viewings, often costs more than the annual increase being argued over. A reliable tenant who pays on time is worth something.
- Think about the deposit. If the deposit equals one month's rent, agree in the annex whether it is topped up to the new amount.
What the tenant can do
- Decline an increase that the fixed-term lease does not provide for, and keep paying the current rent until the term ends.
- Offer a compromise — a smaller increase in exchange for a longer term, or a fixed rent for the coming year.
- Under an open-ended lease — if they do not accept the new price, expect notice, or give notice themselves and look elsewhere.
Tenants' rights and obligations more broadly — deposit, repairs, notice — are covered in our guide for tenants.
Euro and tax
Leases signed in leva remain valid after 1 January 2026 — the rent is now held in euro at the fixed rate of 1.95583, rounded to the cent, with no annex needed. When indexing, calculate directly in euro.
A higher rent also means higher taxable income for the landlord. How it is declared and paid is in our guide to tax on rental income. Keep the annex with the lease — it is the document that explains the change in the amounts.
In short
- A landlord cannot unilaterally raise the rent during a fixed-term lease (Art. 20a ЗЗД).
- An increase happens through a clause in the lease, an annex, or a new lease.
- A good indexation clause names the NSI index, the date, the cap, how notice is given and the rounding.
- An open-ended lease can be ended by either side with notice (Art. 238 ЗЗД) — so a new rent there is a matter of negotiation.
If you let out property and want a lease that deals with increases from day one, or you are looking for a tenant and want a realistic market rent — see how we choose tenants, then call us or come into the office. We will go through the lease and the neighbourhood with you.
Verified November 2026. Inflation figures are NSI data for September 2026 and are updated monthly. This is general information, not legal advice for a specific case.
