The requirements for a Singapore Visa application are:
Completed Singapore Visa application form. You have to answer questions regarding your personal information, marital status, where in Singapore you will be staying, your address in your home country, the purpose of your visit, your intended stay, and so on. You must sign the document yourself. When you arrive at the entry port in Singapore, the ICU could ask you to submit it.
Photocopy of your passport’s bio-data. It has to be in an A4 format.
Photocopy of booked airline ticket or travel itinerary. A4 format.
Passport-size picture of yourself. It must have been taken in the last three months, have a white background, and show you facing forward with a neutral expression. You are not permitted to have headgear unless it is for religious reasons. Even so, the headgear cannot obstruct the face.
Letter of Introduction. This document must be signed by your local contact or strategic partner and be attached to your application. It asks your contact/partner in Singapore to provide your personal information, the reason you want to visit Singapore, how long you will stay, as well as the relationship between you and them.
A credit card. You will use the card to pay for the Singapore visa processing fee. The card must be a VISA or MasterCard.
Yellow Fever Vaccination (If applicable). If you have been to the countries on the table below six days before traveling to Singapore, you will need to show the ICA officers at the entry point that an International Certificate of Vaccination for yellow fever.