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Validation applications čTečka and Tečka

The EU countries have, in order to simplify traveling across Europe, decided to introduce a common Digital EU COVID Certificate (also known as COVID Pass, Digital Green Certificate, Digital COVID Certificate, or also the Certificate). This certificate has been issued since July 1 and is in addition used as a proof of having undergone a test/vaccination or survived a COVID-19 infection within a EU member state. As for other countries than the EU member states, the conditions set by the respective country (page in Czech only) apply.

There are two applications constituting the safe and sound proving principle - one containing a QR code (from the certificate) and the other that reads the code and shows whether the vaccination or Covid-19 test is performed at the required interval - either according to the rules of cross-border movement or within the entrance to stores, establishments, for cultural or sports events, etc. The same applies for having survived a COVID-19 infection as well.

Want to prove yourself using your certificate upon entering an establishment, crossing a state border, etc.? Then...


applies to you,

the application in which the QR code is displayed. It is available on App Store and Google Play.

The application updates its parameters - validation rules and signature certificates of EU countries approx. every 24 hours.

You can upload more certificates (e.g. those of your family members) to Tečka by downloading the certificate to, or you can scan the QR code from the certificate you have already downloaded. The validity of the certificate downloaded in Tečka can be verified even without internet access.

You can find image instructions on how to use the Tečka and čTečka applications and the most frequently asked questions and answers at

Tečka - how to install & use it?

Download the app (App Store & Google Play), log in and connect it with the ISIN system (i.e. the system in which sampling and vaccination points store information about testings and vaccinations carried out). There are three ways to do so, should you not manage it intuitively, you may reach out to the Life Situation page regarding vaccination certificates for a description. Once the app is connected, you will see your certificates (and other persons' ones as well, if you added them the same way as your ones previously) there.

Which certificate types can be viewed using Tečka?

Tečka can store certificates about

  • having been fully vaccinated
  • having undergone a PCR test
  • having survived a COVID-19 infection
  • contraindications for vaccination.

More information about the certificates and their validity can be found in the Certificates section: Certificate of Vaccination - Covid Portal (

Proving of having followed the specific rules when crossing state borders

When entering the territory of the Czech Republic, click/tap the orange banner under the list of certificates stored, scroll down and select the Czech Republic as your destination country. In case of a check, Tečka will then treat your certificate according to the rules valid within the Czech Republic.

When traveling from the Czech Republic to another country, you have to set your destination country in the orange banner to ensure that Tečka will present your certificate as validated according to the rules of that country. However, when performing a check, the local authorities will still use their own check apps and not stick to the colours used by Tečka. Should the rules in your destination country change at the last moment before your arrival, please stay up to date by checking the information stated on the MFA website.

If you experience a technical issue with the app, or need image instructions for downloading the app or certificates into it, you can find the answers to your questions at At the same place you can find the answers to the most frequently asked questions regarding the app as well.

Are you a service provider or organizer of mass events and you want to check the certificates of your visitors or customers? Then...


applies to you.

čTečka can read the QR code from a paper certificate as well as from a certificate that has been downloaded e.g. in your mobile phone, or a QR code generated by the Tečka app. The QR code of your certificate is equipped with a digital signature protecting it against forgery. When a certificate check is performed, the QR code will get read by the checker's mobile phone camera and thus verified - the phone display will light up green if the certificate is valid and red if it is invalid. The certificate details contain the holder's name and date of birth, as well as an information about validity of the certificate.

čTečka (E-reader) – how to install & use it?

To check your customers’ certificates, you can use the validation app čTečka. You can download it for free to your mobile phone or iPad on Google Play and App Storeyou do not need any special device.

The first time you run the application, you must accept the terms of use of the application. After the confirmation, the home screen will appear. Click on the “SCAN QR CODE” button. The first time you run the application, it will request access to the camera – you need to allow the access to be able to scan QR codes. After that, a square will appear on your "camera" screen, point it to the QR code (it does not matter whether it is on paper, phone, watch, etc.). When the QR code is scanned, if the certificate is valid, a green screen will appear; if it is not valid, a red screen will appear.

Proving of having followed the specific rules when crossing state borders

When the person supposed to get checked enters the territory of the Czech Republic, tap the orange banner in your čTečka app and select the Czech Republic as destination country in order to configure your čTečka app properly (to make it use the specific rules regarding crossing state borders).

If you experience a technical issue with the app, or need image instructions for downloading the app or certificates into the Tečka app, you can find the answers to your questions at At the same place you can find the answers to the most frequently asked questions regarding the app as well.

Possible causes of the error message stating that your certificate is invalid

  • it contains an invalid data type, in this case the data are not readable at all and thus cannot be viewed
  • the electronic signature could not get verified - the causes in particular are coded via SIGxxx codes
  • it does not meet the requirements regarding its validity (e.g. due to a too long timespan since the first/second vaccination dose, etc.)
  • Meaning of particular SIGxxx codes when the electronic signature cannot get verified:
  • SIG001 - No information about expiration date in COSE
  • SIG002 - COSE has expired
  • SIG003 - No KID (public key identifier) found in COSE
  • SIG004 - No active KID signature certificate could be found
  • SIG005 - Failed to extract the key from the certificate data
  • SIG006 - Corrupt COSE signature data
  • SIG007 - Signature verification failed

A closing warning note

Certificates issued prior to June 1, 2021, cannot get verified this way. Please download or, if you do not have a new, touchscreen, mobile phone, print out the new ones for you.

Frequent questions about this topic

Why is the original version of the vaccination certificate (issued before June 1st) always invalid?
Why don't I see a booster (or additional) dose certificate in Tečka?
What does Parameter Update mean?
Does the čTečka and Tečka applications require Internet connection?
Does the čTečka application store information from certificates?
Why is the name listed twice in the certificate detail?
What will the app want access to on my phone?
Does it matter which vaccine we are vaccinated with?