Families were £2 a week better off in August compared to the same month a year earlier, according to the Asda Income Tracker.
The increase was the largest annual rise since February 2010, and the average UK family had a disposable income available of £149 a week in August 2012.
The slight improvement was driven by easing inflation on family budgets. Clothing inflation fell over the month and vehicle fuel prices remained down on last year.
The downward inflationary trend has been ongoing since the end of 2011 and combined with reductions in the unemployment rate in this year, has created a general improving trend since September last year.
But household budgets are still under pressure. Families are £9 a week down on the disposable income they had available in 2010.
Asda chief executive Andy Clarke said: “The good news continues for UK families for now at least, with more cash in their pockets than a year ago. However there’s no doubt that budgets are still under pressure with the two-year view showing a worsening picture.”
Slow pay growth and a fragile economic outlook means income growth remains constrained, and increased price pressures on the cost of food and fuel could emerge in the coming months after crude oil and commodity prices rose in August.