If you are a Commonwealth citizen, a British overseas citizen, a British overseas territories citizen, a British national (overseas) or a citizen of Zimbabwe then you can apply for a UK Ancestry visa. With a UK Ancestry visa you can work, study and bring your partner or child.
You must prove one of your grandparents was born in the UK, the Channel Islands or the Isle of Man. You must prove that you are 17 or over, you have enough money without help from public funds to support and house yourself and any dependants also your plan to work in the UK. You must show that you have a grandparent born in the UK, the Channel Islands or the Isle of Man, before 31 March 1922 in what is now Ireland OR on a ship or aircraft that was either registered in the UK or belonged to the UK government
You can claim ancestry if you or your parent were adopted and your parents or grandparents were not married. You cannot claim UK ancestry through step-parents. You can apply for this visa 3 months before you travel. You should get a decision on your visa within 3 weeks when you apply from outside the UK. The fee to apply for the UK Ancestry visa costs £637. You may also have to pay the healthcare surcharge.