Septic Tank Survey Cost

In short: a quick visual check of a septic tank usually costs around £250 to £300. A full pre-purchase survey with a written report and a camera inspection of the pipework typically costs around £400 to £800 including VAT. Emptying the tank so it can be inspected is often charged on top.

These figures come from prices UK survey firms publish, checked in November 2026. Your quote will depend on the property, the system and how easy it is to reach.

What you get at each price level

Basic check (around £250 to £300). An engineer looks at the tank and any accessible chambers and tells you, often verbally, what condition the system appears to be in. It’s useful if you just want reassurance, but it may not give a buyer’s solicitor or lender the written evidence they want.

Full survey with a written report (around £400 to £800 including VAT). This is what most buyers and sellers need. It usually covers:

• What kind of system it is: septic tank, sewage treatment plant or cesspit
• The condition and approximate capacity of the tank
• A camera (CCTV) inspection of the pipework between chambers
• Where the system discharges to, such as a drainage field, soakaway, ditch or stream
• Whether it appears to meet the Environment Agency’s general binding rules
• Photos, a written report and recommendations, sometimes with estimated repair costs

For what the surveyor actually looks at, see our septic tank survey guide.

Extras that can add to the bill

• Emptying the tank. Many surveyors need the tank emptied to see its walls and baffles. Some include this, others charge it separately or ask you to book an emptying company first. Ask before you book.
• Extra manholes or long pipe runs. Some fixed-price surveys cover a set number of inspection chambers and charge for more.
• Testing the drainage field. If the report suggests the drainage field or soakaway is failing, confirming that may need trial holes or a percolation test, which is usually quoted separately.
• Distance and access. Remote properties, tanks under patios or overgrown ground can take longer.

Why a survey is usually worth the cost

A mortgage valuation or homebuyer survey doesn’t assess a septic tank. In England, a septic tank that discharges straight to a ditch or stream doesn’t meet the general binding rules and has to be replaced or upgraded. When a property is sold, the guidance says buyer and seller should agree who does that work as part of the sale. Replacing a system typically runs into thousands of pounds, so a few hundred pounds spent finding out first is usually money well spent. See septic tank replacement cost for what’s involved.

The rules on this page are for England. Wales and Scotland have their own, set by Natural Resources Wales and SEPA.

How to compare quotes

• Check whether the price includes VAT. Some firms quote with it, others without.
• Ask whether the survey includes a written report and a camera inspection, or just a visual check.
• Ask whether emptying the tank is included, and if not, who arranges it.
• Ask whether the report says if the system meets the general binding rules. That’s the question a buyer’s solicitor will usually ask.