Guidance hub · England
Septic tank and off-mains drainage guides
Straightforward information to help you prepare for questions about off-mains drainage during a house sale.
Start with the essentials
NEW · FREESeller readiness checkAnswer nine questions for an instant Green, Amber or Red information-readiness result.
NEW · FREEWhat drainage system do I have?Use observable clues to identify a likely septic tank, treatment plant, cesspool or mains connection.
Selling with no septic tank paperworkWhere to search, what to reconstruct and when further investigation may help.
Free septic tank rules checkerAnswer a few questions to see which rules and next steps may be relevant.
Buying a house with a septic tankQuestions, records and inspections for property buyers.
Septic tank costs and calculatorUK guide prices for emptying, surveys, repairs and replacement work.
New septic tank installation costInstallation, replacement and drainage-field costs, plus the extras to check in a quote.
Selling a house with off-mains drainageIdentify whether you have a septic tank, treatment plant or cesspool and what to gather.
Selling a house with a septic tankWhat to prepare, what to disclose and where to begin.
Selling a house with a sewage treatment plantWhat to gather, what to pass on and when to seek advice.
Selling with a shared septic tankResponsibilities, access, shared costs and records to prepare.
Septic tank selling checklistA practical list of details and records to organise.
Documents for a house saleWritten information, plans, receipts and maintenance records.
Septic tank inspection or surveyWhen a specialist septic system inspection may help and what it can establish.
General Binding Rules explainedThe main Environment Agency rules in plain English.
Organise your own property information
MySepticCheck brings your system details, discharge information, maintenance history and supporting evidence into one organised seller record.
These guides are for properties in England. They provide general information only and do not replace official guidance or professional advice. MySepticCheck is not a compliance certificate, survey, physical inspection or legal or environmental advice.