When you ask a query on this general forum, business etiquette demands the disclosure of your name, designation, the nature of your company or industry, etc. Related to your query, you could have provided the following additional information:
a) Is the person asking for a raise reporting to you? What is your role in the organization? Are you from HR?
b) Do you have a well-designed policy on Performance Appraisal (PA)? If yes, has it been communicated to the employees?
c) At what frequency does the PA take place? Is the outcome of the PA linked to a pay raise? What is the frequency of pay hikes?
d) Why is the employee asking for a raise? What specific achievements have they made? When was their last raise?
e) You mentioned "appreciating the employee's hard work." What does hard work entail? What measurable components are involved? Who benefitted from the employee's hard work?
f) Do you have an employee recognition program? If yes, what parameters do you use to recognize employee contributions? Is an employee's performance noticeable?
Final Comments
Do not decline the employee's request for a pay raise outright. I recommend stating that "as per our company's policy, annual salary increments take place in the month of ____. We will consider your request for a salary increment during that time."
Regards,
Dinesh V Divekar