Buying & Selling
Selling a House With a Septic Tank
What sellers need to disclose about a septic tank, and how to avoid it becoming a problem during the sale.
In short: sellers are expected to disclose what they know about a septic tank’s condition, compliance and discharge arrangement — typically via the TA6 Property Information Form. Getting ahead of this with your own assessment tends to produce a smoother sale than a buyer’s surveyor raising it first.
What you’re typically asked to disclose
The standard TA6 form used in most residential conveyancing asks specific questions about private drainage, including system type, whether it’s shared with other properties, and — since the introduction of the General Binding Rules — compliance-related questions about discharge arrangements.
Why getting ahead of it helps
- Buyers (and their solicitors) increasingly know to ask about private drainage compliance
- A flagged issue discovered mid-transaction can delay completion or trigger renegotiation
- Addressing a known issue, or at least pricing it in upfront, keeps the process predictable
- A recent, documented compliance check or survey is genuinely useful evidence for buyers
If your system may not be compliant
You have options: address it before marketing the property, disclose it and price the sale accordingly, or agree a remedy with the buyer as part of the transaction. See non-compliant septic tank and septic tank replacement for what putting it right typically involves.
Preparing documentation buyers will want to see
- Records of installation, servicing and emptying
- Any existing survey or compliance assessment
- Permit documentation, if the discharge arrangement requires one
Do I have to disclose septic tank problems when selling? + −
You're required to answer property information questions honestly, and misrepresenting known issues can create legal liability after completion. Disclosure is generally the safer approach.
Will a non-compliant septic tank stop my sale going through? + −
Not usually on its own — most buyers and lenders proceed once the issue is understood and, where relevant, priced into the transaction or addressed before completion.
Should I fix the septic tank before or after accepting an offer? + −
Either can work — fixing it beforehand can support your asking price, while disclosing and pricing it in gives buyers certainty. A recent specialist assessment helps either way.
Sources
- Environment Agency — General binding rules: small sewage discharges to the environment
- Law Society TA6 Property Information Form guidance