If your business receives personal data transfers from the EU, including the Republic of Ireland then you will be impacted once the transition period ends.

If your businesses sends personal data transfers to the EU, including the Republic of Ireland the UK Government has confirmed that it will continue to recognize the protection offered in EU member states by virtue of the EU GDPR.
Therefore, you can continue as normal.

The new regulations come into place from 1^st January 2021.

For more information on this topic, please follow the links below.

Dept of Economy NI

https://www.economy-ni.gov.uk/uk-exit-eu-preparing-transfer-personal-data

Invest NI

https://www.investni.com/media-centre/features/preparing-eu-exit-data-protection-0

Intertrade Ireland – Brexit Voucher Scheme

https://intertradeireland.com/brexit/funding/voucher