AMP Bank has joined the growing number of lenders offering commission "specials" to brokers to generate higher volumes.On Monday, the bank started paying an extra 20 basis points of upfront commission on loan applications from third-party originators. The offer runs until November 30.Mortgage Choice chief financial officer Susan Mitchell said it was becoming increasingly common for lenders to offer brokers short-term volume incentives. For example, at the moment Westpac has a 10 bps bonus offer running until September 30.AFG's general manager of sales and operations, Mark Hewitt, said AFG brokers were currently receiving higher upfront commissions, on a short-term basis, from AMP Bank, Westpac, ME Bank and a specialist commercial lender, MKM Capital.ME Bank is offering increases of 10, 20 or 30 bps, depending on the volume of applications.Westpac has also tied its 10 bps increase to a volume target.Hewitt said short-term commission incentives gave lenders flexibility to respond to their funding situation, their risk appetite or their budget requirements."Specials allow them to dial the business up and down to meet their targets," he said.Overall, the trend is for higher commissions. Mortgage Choice reported that over the past year Bankwest increased its upfront commission payment from 50 to 70 bps, and Macquarie Bank increased its upfront commission from 60 to 65 bps.Hewitt said: "I have never seen it more competitive. It is a very positive environment for borrowers."Some lenders have reported that higher commissions and marketing costs have put pressure on their margins. Homeloans reported a drop in earnings in the year to June, partly due to an increased investment in marketing and distribution.In its financial report, the company said: "Intense competition among mortgage lenders has seen aggressive discounting of both establishment fees and headline rates, not to mention adjustment of commission rates and structures, to attract business."