This is an old thread but still relevant for others who need info. So, renewal for WFP is every 52 weeks. Although theres no change in WFP payments during the 52 weeks where your household income increases, WFP for the next 52 weeks is based on averaging out the income for the previous 52 weeks. On renewal you'll be asked for 2 most recent payslips and the P60 equivalent for the prev tax year to Dec. Note, you are not obliged to notify The Dept of this new job during the 52 weeks but it will be relevant as an increase in household income when renewal for WFP comes around again.