Depending on your nationality, you’ll either:
have to apply for a Standard Visitor visa before you travel to the UK
be able to visit the UK for up to 6 months without needing a visa
You can check if you need a visa before you apply.
You can visit the UK as a Standard Visitor for tourism, business, study (courses up to 6 months) and other permitted activities.
Apply for a Standard Visitor visa
You can apply for a Standard Visitor visa, or if you visit the UK regularly you can choose to apply for a long-term Standard Visitor visa instead.
The earliest you can apply is 3 months before you travel.
More information you can refer to: https://www.gov.uk/standard-visitor
Letter of Invitation:
A Letter of Invitation is a proof that your paper submission and registration application are accepted by the conference committee board. It perhaps could help with your visa application. However, it does not guarantee you a visa.
Letter of Guarantee:
A Letter of Guarantee is an individual/party agrees to be legally and financially responsible for your staying during your visit in the country you’re going to. ICVARS does not and will not provide such document.
In conclusion, please take note that ICVARS does not issue organization registration letter, guarantee letter, schedule of staying letter, local sponsor letter, governmental format invitation letter, and etc.
Any violation of the ICVARS visa application regulations is absolutely not tolerant.
Should your application be denied, ICVARS cannot change the decision of the Ministry of Foreign Affairs, nor will we engage in discussion or correspondence with the MOFA or the Embassy on behalf of the applicant. The registration fee cannot be refunded when the VISA application of individual being denied.