A polite/honorific expression for contacting or getting in touch (often used in business or when speaking to superiors).
詳細が決まり次第、ご連絡いたします。
I will contact you as soon as the details are decided.
何か問題があればご連絡ください。
Please get in touch if there are any problems.
先日はご連絡いただき、ありがとうございました。
Thank you for getting in touch the other day.