The Central Bank has warned that Irish creditors with direct debits in place for UK customers may need to provide their banks with additional information to avoid payment requests being rejected.
It follows the end of the Brexit transition period last night.
"The Central Bank has engaged extensively with payment service providers, UK supervisory authorities and industry representative bodies to emphasise the mandatory requirements for additional information and to monitor progress towards compliance," the regulator said in a statement.
In recent weeks, the Banking and Payments Federation Ireland had warned that as many as 140,000 recurring direct debits were at risk after the UK became a third country.
The additional information typically required is the address of a customer.
The Central Bank also reminded the public that while most financial services providers are well prepared for the end of the transition period, UK authorised firms can no longer provide financial services to Irish customers on a cross-border basis, known as passporting.
"Any customer who currently uses the services of a UK-based financial services provider, and has not yet been contacted by them, is advised to contact their provider to confirm whether they have obtained all necessary authorisations to allow them to continue to provide services to their Irish customers," the bank stated.
When it comes to insurance, the bank said legislation put in place by the Government includes a temporary run-off period of up to 15 years, during which policies held by Irish customers with UK service providers will remain valid, provided the insurer meets conditions.
However, in the vast majority of cases where a UK policy is shorter than 15 years, they will not be renewable when they expire.
Central Bank Deputy Governor, Ed Sibley, said the band had actively engaged with firms on the need to prepare for the potential impact of Brexit since the referendum.
"While we have worked to minimise the impact of Brexit on the financial services industry it is possible that there may be some residual disruption to financial services in the coming days or weeks," he said.
"We will continue to monitor for any potential issues arising and will work to ensure that these issues are managed on a timely basis."