BM Solutions will pay £500 cashback on selected two-year fixed buy-to-let products from 3 April.
Mortgage applications eligible for cashback will be paid through conveyancers on completion.
Applications must be made by 28 May 2017.
The lender has also added two new two-year buy-to-let mortgage options.
At up to 60 per cent LTV borrowers can get a rate of 2.09 per cent and at up to 75 per cent LTV the rate will be 2.49 per cent.
Both loans have a £495 fee and the £500 cashback will apply.
BM Solutions is also bringing in new five-year let-to-buy products.
At up to 60 per cent LTV, lenders can get rates of 2.39 per cent. At up to 75 per cent LTV rates are 2.89 per cent.
Both options have a £1,995 fee.
The lender has also cut rates by up to 0.30 per cent on its buy-to-let five year loans up to 60 per cent LTV and by up to 0.20 per cent on buy-to-let five-year loans up to 75 per cent LTV.
BM Solutions head Phil Rickards says: “Helping brokers add value for customers is not only fundamental to our ongoing investment in the buy-to-let market, but part of our wider phased plans to support brokers in writing quality business as the landscape continues to evolve.”