If someone is required to disclose a criminal record on a visa or entry application and deliberately does not, the consequences can be much more serious than the criminal record itself.

Possible consequences include:

• Refusal of entry at the border. If immigration officers discover the omission before or upon arrival, the person may be denied entry and sent back on the next available flight.
• Visa refusal or cancellation. If the omission is discovered after a visa has been issued, the visa may be cancelled.
• Removal or deportation. If the person has already entered the country, they may be removed under that country’s immigration laws.
• Future travel difficulties. Many countries ask whether a person has ever been refused a visa, refused entry, or deported. Answering “yes” can make future applications more difficult.
• Immigration penalties. Some countries treat knowingly providing false or misleading information as immigration fraud or misrepresentation, which can result in bans on re-entering for several years or longer.
• Possible criminal consequences. In some jurisdictions, intentionally making a false declaration on an immigration form can itself be a criminal offence, separate from the original conviction.

Whether authorities discover an undisclosed conviction depends on many factors, including:

• Information-sharing agreements between countries.
• Biometric checks (such as fingerprints or facial recognition).
• Police certificates required during visa applications.
• Previous travel history and immigration records.

The likelihood of detection varies by country and visa type, so it’s not possible to say whether a particular omission would be discovered.

If someone realizes they made an error or omission on an application before travelling, it’s generally better to correct it with the relevant immigration authority than to hope it won’t be noticed.