Calibration of meters: Deadlines, rules and what is at stake if they are not followed
Everything about the mandatory verification of meters in rentals. Billing periods for water meters, heat meters, legislation and practical advice for landlords.
"Certification? This only applies to factories and large companies, right?" – Unfortunately, this is a common mistake. As a landlord, you are responsible for ensuring that all meters in the rented apartments have valid verification. And if they don't have it, you can have a serious problem - from an invalid bill to fines.
In this article, I will explain to you what benchmarking is, what are the legal deadlines, how to know the validity of the meter and what to do if you have missed the deadline.
What is benchmarking (verification) of the meter
Definition: Betting meters") is an official process in which an authorized testing facility confirms that the meter measures correctly and meets the specified requirements.
Result: A verification mark (sticker or seal) with the validity date is attached to the meter.
Why we do it:
- Ensuring fair measurement
- Protection of consumers and suppliers
- Legal obligation for business measurement
Legislative framework
Act on Metrology (No. 505/1990 Coll.)
Establishes the obligation to use certified meters for:
- Measurement in business relations
- Setting the price for services
- Consumption billing
Residential water meters and heat meters used for cost accounting fall into the category of "specified meters" and MUST be verified.
Decree No. 345/2002 Coll.
Sets instrument-specific verification periods; consult the current UNMZ schedule for the exact type, category and use.
Act No. 67/2013 Coll.
O on services in apartments - requires consumption measurement using legal meters.
Overview of validity periods
Water meters
| Water meter type | Verification period |
|---|---|
| Cold or hot water meter | Check the current UNMZ period for the exact instrument category and use; do not infer it from temperature alone |
Why is TUV shorter? Hot water puts more stress on the meter mechanism (deposits, corrosion) and reduces accuracy faster.
Heat meters
| Heat meter type | Verification period |
|---|---|
| Residential or ultrasonic heat meter | Check the current UNMZ period for the exact instrument category and use |
Ratio indicators
| Type | Deadline |
|---|---|
| Electronic indicator | Check the current rules for the exact device and billing method |
| Evaporation Indicator | It changes every year |
Note: Ratio indicators are NOT meters in the sense of the Metrology Act, but are used for billing according to Decree No. 269/2015 Coll.
Electricity meters (subsidiary)
| Type | Deadline |
|---|---|
| Electric meter single-phase | Check the current UNMZ period for the exact instrument category |
| Electric meter three-phase | Check the current UNMZ period for the exact instrument category |
How to know if the meter is verified
Verification mark
On the meter you will find:
Green sticker with:
- Year and month of expiry (e.g. "12/2026")
- CMI logo or authorized center
- Identification number test rooms
Seal/screw lock prevents manipulation
Where to look
- On the front panel of the meter
- On the side of the case
- On the connection screws
Example
The sticker shows "06/2025" → The meter is valid until June 30, 2025.
What happens after the deadline
Legal consequences
The meter may no longer be valid for direct billing. Follow the current metrology and service-billing rules, including any required replacement, verification or fallback calculation. A faulty or non-compliant device does not automatically invalidate every settlement; penalties and remedies depend on the current law and facts.
Practical consequences
- You lose in a dispute
- You have to return overpayments
- Loss of credibility
- Additional exchange costs
Who is responsible for verification
In the rental apartment
Landlord – As the owner of the property, he is responsible for the condition of the meters.
In an apartment building (SVJ)
SVJ/BD – For common meters (foot water meter, house heat meter)
Individual owners – For apartment meters (if they are owned)
Landlord – For meters in rented bytě
At the supplier
The energy supplier manages the billing meters (main electricity meter, gas meter) and is responsible for their verification.
How to ensure a valid verification
Option 1: Exchange for a new meter
Procedure:
- You purchase a new meter with a valid
2 verification. You let it install
- You dispose of the old meter
Advantages:
- Fast
- New = reliable
- Mostly cheaper than grading
Typical costs:
- Water meter: Kč 500–1,400 (including installation)
- Heat meter: Kč 4,000–10,000
Option 2: Rechecking the existing meter
Procedure:
- Dismantling the meter
- Sending to an authorized testing room
- Inspection and possible adjustment
- Reassembly
Advantages:
- Preservation of the original meter
- It can be cheaper with expensive meters
Disadvantages:
- Time-consuming (days to weeks)
- The meter may not pass
- Necessity of a replacement measurement
Costs:
- Verification: 200–500 Kč
- Labor: Kč 600–1,600 (2x assembly)
- Total: Kč 800–2,100
Authorized testing facilities in the Czech Republic
Czech Metrological Institute (ČMI)
State testing facility with branches throughout the country.
- Prague, Brno, Ostrava, Plzeň, České Budějovice
Authorized metrology centers
Private companies authorized to verify meters:
- ENBRA a.s.
- Maddalena CZ s.r.o.
- Techem s.r.o.
- ista Česká republika s.r.o.
Tip: For a larger number of meters, arrange bulk exchanges with a discount.
Records and monitoring deadlines
Manual records
Create a table with columns:
- Production number
- Type of meter
- Location (apartment, address)
- Date of validity
- Date of next exchange
Disadvantage: You easily forget.
Automated records
Real estate management software:
- Notice before expiration
- Connection with readings
- Exchange history
- Documents (verification sheets)
Frequently asked questions
Can the meter be used after the expiration date?
Technically yes, legally no. The meter works, but by law it cannot be used for billing.
What if the tenant refuses replacement?
The tenant is obliged to enable the maintenance of the apartment, including the replacement of meters. Notify him in writing and, if necessary, consult a lawyer.
Does the deadline apply from the date of manufacture or installation?
From the date of verification (indicated on the label). It may differ from the date of installation.
Can I verify the meter myself?
No. Verification can only be performed by an authorized testing laboratory or the Czech Metrological Institute.
What about a meter without a sticker?
It is considered unverified. You must either have it verified or replaced.
Special cases
New buildings
Meters installed in new buildings have a valid verification. The period starts from the date of verification (not approval).
Renovation
When renovating the distribution system, use the opportunity to install new meters.
Inheritance/purchase of property
When taking over the property, check the validity of all meters. These are your costs.
More flats = more meters
For larger objects, a replacement schedule pays off - for example, 1/3 meters per year.
Inspections ČMI
When will they come
- Random inspections
- Based on a complaint
- As part of targeted actions
What they check
- Validity of verification
- Integrity of seals
- Correctness of installation
- Type conformity
Penalties
- Warning and deadline for correction
- Fine: 10,000 – 1,000,000 Kč
- Repeated violation: higher rates
Practical example: Schedule for residential house
10 apartments, each has:
- 1× cold-water meter (period: check the current UNMZ schedule)
- 1× hot-water meter (period: check the current UNMZ schedule)
- 1× heat meter (period: check the current UNMZ schedule)
Strategy:
- Year 1: Exchange of heat meters (10 pcs)
- Year 2: Exchange of DHW water meters (10 pcs)
- Year 3: Replacement of SV water meters (part)
- Year 4: Another cycle of heat meters
Cost distribution over time and predictable budget.
Summary
| Gauge | Deadline | What to do |
|---|---|---|
| Water meter NE | Check current UNMZ schedule | Replace or verify as permitted |
| Water meter DHW | Check current UNMZ schedule | Replace or verify as permitted |
| Heat meter | Check current UNMZ schedule | Verify or replace as permitted |
| Electric meter | Check the current UNMZ period | Usually managed by the supplier |
Meter calibration is not bureaucratic harassment - it is to protect you and your tenants. With good records, you will not miss any deadline and the bill will always be legally correct.
> Czech-law scope and editorial note: Legal, tax, accounting, tenancy, service-charge, condominium, metrology, insurance and data-protection statements in this article refer to the Czech Republic and the rules effective for the relevant date. Figures and examples are illustrative, not legal or tax advice. Verify current rules with the relevant Czech authority or a qualified adviser.
> Metrology and heat clarification: Verification periods depend on the instrument type and current UNMZ rule. Heat allocation uses the current Czech decree and may use a 40%, 50% or 60% basic component according to building energy performance, with possible adjustments; hot-water allocation is separate. Do not treat a 30/70 or ±20% statement as universal.