DMBM524050 - Debt and return pursuit: CIS: timeline of events You should check the other guidance available on GOV.UK from HMRC as Brexit updates to those pages are being prioritised before manuals. On the 19th of each month, the contractor must submit the monthly returns. On or around the 29th of each month, ETMP will issue penalty notices following the CIS computer system sending: details of returns that were filed late or are still outstanding to ETMP for the issue of a penalty as appropriate a work item to IDMS for each return outstanding. 30 days from issue of penalty notice, ETMP will pass a work item to IDMS for each penalty still outstanding.