Its five-year fixed products for standard buy-to-let have been reduced by up to 0.25 per cent.
Pricing now starts at 3.04 per cent for a mortgage at 65 per cent loan to value (LTV) and no application fee.
For two-year fixed options, rates begin at 2.84 per cent.
Rates for specialist new builds, flats above commercial properties, homes in multiple occupancy (HMO) and multi-unit freehold blocks (MUFBs) begin at 3.14 per cent for a two-year fixed at 65 per cent LTV and 3.43 for the five-year fixed equivalent.
These products are available up to 75 per cent LTV through intermediaries but the lender will still offer its packager exclusive products at 80 per cent LTV.
Paul Fryers, managing director at Zephyr Homeloans, said: “Our broad range of products offer several, flexible options to fit individual needs for landlords and property investors.
“Reducing the rates across a majority of Zephyr’s mortgage products reinforces our position as one of the more competitive lenders in the UK buy-to-let market.”