Fiance Visas last for 6 months and they are granted under the assumption that you will marry your partner within the validity period of the visa.
You must apply for another immigration permission to remain in the UK after your Fiance Visa expires. The simplest is to switch from the UK Fiance visa to the Spouse Visa, which grants holders 30 months of residence in the UK. You can look for employment and study in the UK as a Spouse Visa holder, without any restrictions.
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.
You must have a passport or travel document that is valid for the whole of your stay in the UK. There must be a blank page in your passport for your Standard Visitor visa.
Once you’ve applied online, proved your identity and provided your documents, you’ll usually get a decision on your visa within 3 weeks.