Typical minimum criteria for buy-to-let mortgages include:
A deposit of at least 20% of the property value, although you will find better deals if you have a larger deposit.
A minimum rental income of 145% of the mortgage payment.
Earnings of more than £25,000 per year.
A good credit record without excessive additional borrowing on credit cards and other mortgages.
If you are an existing property investor; a summary of the properties values, outstanding mortgage balances, monthly mortgage payments and monthly rental income.