The range includes improved options for first-time landlords, buyers of houses in multiple occupation and multi unit freehold blocks, expats, and holiday and Airbnb landlords.
The new products, which are available for individuals and limited companies, start from 3.79 per cent up to 70 per cent loan to value (LTV) with a maximum loan of £500,000.
It also works to a debt service coverage ratio (DCSR) of 125 per cent up to 70 LTV for limited companies or limited liability partnerships (LLPs) and lower-rate taxpayers.
A rental stress calculation based on five per cent or the pay rate of a five-year fixed product starting from 3.99 per cent, is used.
Remortgages come with reduced legal fees and faster completions up to £500,000.
Properties owned for less than six months, high rise flats over five storeys, ex-local authority flats and deck access flats are considered.
Jason Berry (pictured), interim group sales director at Crystal, said: “During lockdown, West One has certainly been there for Crystal and our brokers.
“They have continued to underwrite and take a pragmatic view on cases which has ensured our brokers have been able to serve their customers through these incredible times.
“These new products underline the strength of the relationship we have and we are sure they will prove popular and provide greater options for property investors.”