The purchase range, available for first-time buyers and home movers, was due to end at 8pm this evening but will now run until 8pm on Tuesday 10 November.
Two five-year fixed rates with a product fee of £995 and free valuation are available.
For loans up to £500,000, borrowers can access a rate of 3.79 per cent and for loans between £500,001 and £600,000, the rate is 3.89 per cent.
To help manage its service levels, Accord cut its maximum loan to income (LTI) multiple down to 4.49 for incomes of £60,000 and above.
The cap was previously five times income and the change puts higher earners on the same level as those earning below £60,000.
Jeremy Duncombe, (pictured) director of intermediary distribution at Accord Mortgages, said: “Since launching on Monday morning, we’ve seen the positive impact our increased capacity has had on service levels.
“The recent changes we made to loan to income caps, as well as having a boosted underwriting team means we are ahead of where we planned to be and so have made the decision to extend the offering for longer. We hope advisers can support more clients get the homes they want.”