To find out whether there is a ban, you need to submit a request to the relevant authorities. 

There is a specific and exhaustive list of entities that can apply such a ban. They include:

• The Border Guard Service of Ukraine;
• The Migration Service of Ukraine;
• The Security Service of Ukraine;
• National Police.

On the legal status of foreigners and stateless persons 

https://zakon.rada.gov.ua/laws/show/3773-17

Article 13 Grounds for banning the entry of foreigners and stateless persons into Ukraine

1. A foreigner or a stateless person shall not be allowed to enter Ukraine

in the interests of ensuring the national security of Ukraine or the protection of public order, or the fight against organised crime;

{Paragraph two of part one of Article 13 as amended by Law No. 671-IX of 04.06.2020}

if it is necessary for the protection of health, rights and legitimate interests of citizens of Ukraine and other persons residing in Ukraine;

if such a person has provided knowingly false information or forged documents when applying for entry into Ukraine;

if such person's passport document or visa is forged, damaged or does not comply with the established standard or belongs to another person;

if such a person has violated the rules of crossing the state border of Ukraine, customs rules, sanitary norms or regulations at the checkpoint of the state border of Ukraine or has failed to comply with the lawful requirements of officials and officers of the state border protection bodies, customs and other bodies exercising control at the state border;

{Paragraph six of part one of Article 13 as amended by Laws No. 406-VII of 04.07.2013, No. 440-IX of 14.01.2020}

if during the previous stay on the territory of Ukraine, the foreigner or stateless person failed to comply with the decision of a court or public authorities authorised to impose administrative penalties, or has other unfulfilled property obligations to the state, individuals or legal entities, including those related to the previous expulsion, including after the expiration of the ban on further entry into Ukraine;

if such a person has entered or left the temporarily occupied territory of Ukraine or the area of the anti-terrorist operation in violation of the procedure established by the legislation of Ukraine or has attempted to enter or leave these territories outside the entry-exit control points;

{Part one of Article 13 is supplemented by paragraph eight according to the Law No. 1207-VII of 15.04.2014; as amended by the Law No. 2293-VIII of 27.02.2018}

2. If there are grounds specified in paragraphs two, seven and eight of part one of this Article, information about a foreigner or stateless person shall be entered into the database of persons who are not allowed to enter Ukraine or temporarily restricted from leaving Ukraine in accordance with the legislation of Ukraine.

{Part two of Article 13 as amended by Law No. 1207-VII of 15.04.2014}

3. The decision to ban entry to Ukraine for a period of three years shall be taken by the central executive body implementing the state policy in the field of migration (immigration and emigration), including counteraction to illegal (irregular) migration, citizenship, registration of individuals, refugees and other categories of migrants defined by law, the Security Service of Ukraine or the state border protection body, or an authorised unit of the National Police of Ukraine. In case of failure to comply with the decision to ban entry into Ukraine, foreigners and stateless persons are prohibited from further entry into Ukraine for ten years, which is added to the part of the period of prohibition of entry into Ukraine that has not expired by the time of the repeated decision to ban entry into Ukraine.

{Part three of Article 13 as amended by Laws No. 2293-VIII of 27.02.2018, No. 671-IX of 04.06.2020}

Article 14 Return of foreigners and stateless persons who are not allowed to enter Ukraine

1. Foreigners and stateless persons who are not allowed to enter Ukraine, when attempting to enter Ukraine at a checkpoint across the state border of Ukraine, shall not cross the state border of Ukraine and shall return as soon as possible to the state from which they arrived or to the state that issued their passport document.

If it is impossible to return a foreigner or stateless person immediately, they stay at the checkpoint across the state border of Ukraine until their return.

Such foreigners and stateless persons shall have their passport document stamped with a note on the prohibition of entry into Ukraine for the period specified in the decision taken in accordance with part three of Article 13 of this Law.

2. Foreigners and stateless persons in case of illegal crossing of the state border of Ukraine outside the checkpoints across the state border of Ukraine shall be detained and, if their violation of the legislation of Ukraine does not provide for criminal liability, returned to the country of previous stay in accordance with the established procedure.

Such foreigners and stateless persons are banned from entering Ukraine by the state border protection authorities for a period of five years. Information about them shall be entered in the database of persons who are not allowed to enter Ukraine or temporarily restricted from leaving Ukraine in accordance with the legislation of Ukraine.

{Paragraph two of part two of Article 14 as amended by Law No. 2293-VIII of 27.02.2018}

3. During the detention, the state border protection bodies shall ensure fingerprinting and, if necessary, other biometric data of foreigners and stateless persons in accordance with the law.