This Practice Note will assist in-house lawyers in Ireland in the practical application of legal professional privilege (LPP) within their business. This note addresses:•legal advice privilege, and•litigation privilegebeing the two forms of LPP, and considers:•the duration of each type•how LPP may be waived, and•any exceptions to the application of LPP to communications of in-house lawyersWhat is LPP?LPP is a composite term for:•legal advice privilege, and•litigation privilegeLPP protects the confidentiality of written and oral communications from disclosure to a third party.Legal advice privilegeLegal advice privilege protects confidential communications between a lawyer and their client, which are made for the purpose of giving or receiving legal advice. Such communications may be oral or written.Duration of legal advice privilegeLegal advice privilege attaches to the communication indefinitely and persists beyond the lawyer/client relationship. Therefore, once properly asserted the communication