Increasing the maximum limit to £400 would help first time buyers or anyone with a Help to Buy ISA to save for their first home quicker; as saving for 5% of the average house price can take 5 years. Putting £400 a month into the account would be a good way to simulate paying for a mortgage every month as the current £200 isn’t really a realistic mortgage payment and will cut in half the amount of time you have to wait to build up 5%.You could still deposit £200, but some people can put £400 away.