The lender said that the application fee will fall from £2,999 to £2,499 across all LTVs.
For loans between £250,000 and £1,000,000, the fee will stay at £3,999.
It added that all the mortgage rates across its range will remain the same.
David Finlay, intermediary managing director for Barclays, said: “Due to the increase in demand for rental properties we are regularly reviewing our products to ensure the competitiveness of our buy-to-let mortgages in the market place.
“With a 22% rise in the number of buy-to-let products available, today’s reduction helps to support the buy to let market further.”