Subject: Regretfully Declining Your Invitation to the Social Event Dear [Name of the Inviter], I hope this letter finds you well. I would like to express my sincere gratitude for extending an invitation for me to attend the [Insert Event Name] on [Insert Date and Time]. I am truly honored that you thought of me and appreciate the effort put into organizing such a special occasion. However, with regret, I must decline your kind invitation. Please understand that my inability to attend the event is not a reflection of my lack of interest or appreciation for your thoughtful gesture. Allow me to explain the reasons behind my decision. [Type 1: Business Commitments] I am currently dealing with some unforeseen business commitments that clash with the date of the event. As [explain your business obligations], I am unfortunately unable to rearrange my schedule in a manner that would enable me to attend your event. Please accept my sincerest apologies for any inconvenience this may cause. [Type 2: Prior Engagement] Regrettably, a long-standing prior engagement has been scheduled for the same day as your event. As much as I would love to join you on this occasion, I am bound by my earlier commitment, which I cannot cancel or reschedule. I apologize for any disappointment caused by my absence. [Type 3: Personal Circumstances] Unfortunately, due to unforeseen personal circumstances, I find myself unable to attend the event. [Kindly keep the reason for your personal circumstances general without divulging too much personal information]. I hope you understand that it is beyond my control and that I would have loved to celebrate this special occasion with you. Please know that my decision to decline your invitation was not an easy one. I assure you that I hold great regard for your friendship and I look forward to the opportunity to celebrate with you at a future event. Once again, I extend my sincere apologies for not being able to attend your event, and I hope it is a tremendous success. Thank you for your understanding. Wishing you all the best and looking forward to catching up soon! Warm regards, [Your Name]