You can choose to apply for a long-term Standard Visitor visa if you visit the UK regularly. This visa lasts 2, 5 or 10 years. You can stay for a maximum of 6 months on each visit.
If you’re under 18 years old when you apply, your long-term Standard Visitor visa will only be valid for up to 6 months after you turn 18. You cannot get a refund on the fee.