The UK Student Visa
explained simply.

• You must have an unconditional or conditional offer before applying
• The CAS is only issued after you accept the offer and pay the deposit
• The IHS (Immigration Health Surcharge) must be paid upfront — approximately GBP 776 per year
• You can apply up to 6 months before your course starts

Apply as soon as your CAS is issued — processing takes 3 weeks on average but can take longer in peak periods (June to August). Do not delay.