Help to Buy (HTB) is a government scheme. It allows first-time buyers of a new build to borrow up to 20% of the property's value (or 40% in London). The loan is directly from the government and you pay the capital back when you sell.
In 2015, the government launched the HTB ISA, a savings account designed specifically to help you save for the deposit on your first home. As long as you follow the scheme rules and can prove that you've completed on your purchase, the government will pay a 25% bonus on your saved capital once you close the ISA.
HTB Equity Loan - The HTB Equity Loan scheme is available for new build properties with a purchase price of up to £600,000. The government will lend you up to 20% of the cost of a brand new home, meaning you only need a 5% cash deposit and a 75% mortgage. The equity loan is interest-free for the first five years. From year six, the government charges a fee of 1.75%, then RPI plus 1% per annum.
Help to Buy ‐ London - If your dream is to own a home in the capital, an adapted version of the Equity Loan scheme could be for you. The Government introduced a London-only version of Help to Buy in February 2016, available across all Greater London boroughs. You're eligible if you have a 5% deposit to put down on your new home. This version has an upper loan limit of up to 40% of your purchase price rather than the standard 20%, and works the same as the nationwide scheme.
With Help to Buy ‐ London, you won't be charged loan fees on the 40% loan for the first five years of owning your home, apart from a nominal monthly £1 per month fee.