Always make it official in writing. Here's a sample letter you could use.
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Month XX, 2004
To: Organizationname - Human Resources Department
CC: Firstname Lastname - Title Of Your Boss
From: Caitlin Boyle
Subject: Letter of Resignation
I would like to thank you for the opportunity to have been part of _______ for the past ____, however, effective Month XX, 2004 I will no longer be able to continue my employment with your company.
Over the course of the past year I?ve had the opportunity to develop my skills as a __________?and to watch as the company quickly became one of the most successful Organizationtype in Townname.
While I wish I could continue my employment with Organizationname, I am ___________ that will require my undivided attention. Clearly at this stage in my life that has to be my priority.
Once again, thank you for the opportunity to have been part of the Organzationname team. Perhaps our paths will cross again in the future.
Kind regards,
Caitlin Boyle