Can recommendation letters from my college principal and seniors at my organization be sufficient for my application in UK for a Master's?

Yes, recommendation letters from your college principal and seniors at your organization can be sufficient for your UK master's application if they meet university requirements.

Most UK universities ask for:
- One academic reference (from someone who taught or supervised you at degree level, such as your principal)
- One professional reference (from a current or former employer or senior colleague)

Both referees should know you well and provide detailed, specific insights into your academic and professional abilities. Letters must be in English and usually submitted directly by the referees.

If you have been out of higher education for several years, some universities may accept two professional references.