The number of UPI transactions you can do per day depends on two factors:
NPCI limit: The National Payments Corporation of India (NPCI), which governs UPI, sets a general daily limit of Rs. 1,00,000 (one lakh).
Your bank's limit: Individual banks can set their own lower daily limits for UPI transactions on your account. This could be anywhere between Rs. 25,000 and Rs. 1,00,000.