Information about the number of residents of Bassetlaw constituency who have repaid a tax credit overpayment, and the sum of overpayments outstanding, is only available at disproportionate cost.
Estimates of the number of families with tax credit awards, including information on the annual number and value of tax credits overpaid and underpaid by parliamentary constituency, is available in the HM Revenue and Customs publications "Child and Working Tax Credits Statistics. Finalised Annual Awards. Supplement on Payments. Geographical Analyses". These publications are available at:
http://www.hmrc.gov.uk/stats/personal-tax-credits/cwtc-geog-stats.htm