The product is for landlords with up to 20 properties with a combined value of £5m with Precise, however there no limit on the size of portfolios with other lenders.
Popular places included Slough, Berkshire, where 46% of renters moved from the capital.
After the applicant has been with Castle Trust for 12 months they can request for the lender to review their credit history to offer a cheaper rate in a lower tier if possible.
The Stockport-based society offers mortgages for regulated buy-to-let, interest-only, minor adverse, into retirement and interest-only retirement.
Click Tenant is a new venture from the team behind Student Tenant, which links up university students and landlords.
The product comes with an application fee of £199 and a completion fee of £1,800.
Property Master, which launched four months ago, uses algorithms to match buy-to-let landlords with 90 lenders offering more than 2,000 mortgages.
This represents 79% by value of completing buy-to-let purchases, up from 73% in Q2.
The service enables lenders to measure the value of a portfolio, asset by asset for trading, asset management or risk management purposes.
Clients looking to remortgage a property up to the value of £500,000 will be refunded within 30 days of the mortgage completion, while they will also get a fee assisted legal service via Optima Legal.