The mutual is ahead of its full year target of £177m, with new mortgage lending contributing to a £35m growth in mortgage balances to £655m.
Net mortgages applications also totalled £92m, more than half way towards the full year target of £175m.
Hinckley and Rugby also retained 74% of customers who reached the end of their special mortgage scheme, without the society offering specific retention products.
A spokeperson from Hinckley and Rugby told Mortgage Solutions that existing customers who are approaching the end of the special period of their mortgage can move onto another product online via the website after having received an invite letter.
Fixed rates were the most popular mortgage type in the six months from December to May, with almost 60% of advances at or below 75% LTV.
Hinckley and Rugby chief executive, Chris White (pictured), said: “Achieving a retention rate where almost three out of every four mortgage customers are choosing to stay with us shows how competitive we remain and how hard our staff work to provide an outstanding service.
“We’re on track to achieve the challenging targets we set for ourselves, against a backdrop of a very competitive mortgage market where rates have not risen despite the increase in the Bank of England base rate late last year.
“Whatever happens next to the Base Rate, and when that is, the mortgage market will continue to be one where we need to offer competitive products, manual underwriting that looks at applications in the round and excellent service to intermediaries and customers.”
The growth in lending was funded by net retail savings receipts of £19m, with the balance coming from existing liquidity, Bank of England funding facilities and the wholesale market.