Four products are available on two-year and five-year fixed rates between 85% and 90% loan-to-value (LTV).
All four have a £999 product fee with rates starting at 2.15% and early repayment charges (ERCs) also apply.
The cashback incentive will be paid directly to borrowers within 30 days after completion of their mortgage.
The mutual has also reduced rates by 0.10% on its five-year fixed residential, offset and first-time buyer members’ only mortgages.
Director of intermediaries Kevin Purvey said: “Our £500 cashback incentive on our two-year and five-year fixed rate mortgages will help customers with the cost of moving home, something which proved very popular with our intermediaries last year.”