You can drive in Great Britain until you’re 70. If you’re 68 or over when you become resident, you can drive for 3 years.
After this time you must exchange your licence.
Order form D1 from the Driver and Vehicle Licensing Agency (DVLA).
Send the form, the £43 fee and any documents you need (including your driving licence) to the address on the form.
You should get your new licence within 3 weeks.
You can only drive in Great Britain with a non-EU licence for 12 months after you arrive.