Smart Toilet Buying Checklist UK: Pan Fit, Power and Support

Short answer

If your current toilet is in good condition and there is a way to get power to it, an electric bidet seat is the cheapest and simplest way to get a warm wash. A complete smart toilet may suit a replacement or refit, but an installer should assess the exact model and what existing services can be reused.

Seat, complete toilet or attachment?

Electric bidet seat (retrofit)

This replaces your normal toilet seat. It has a heater for the wash water, a nozzle that slides out underneath you and usually a heated seat. Better models add a warm-air dryer, a deodoriser and a remote. It connects to the toilet's cold water feed with a T-valve and needs mains power.

Good if: you like your current toilet, rent or may move, or want to spend a few hundred pounds rather than a few thousand. Watch for: a visible cable and hose at the side of the toilet, and a pan shape that the seat does not suit.

All-in-one smart toilet

The wash technology is built into the toilet itself. In the UK most are wall-hung, with the cistern, water feed and power hidden in a frame behind the wall. They look neater, are easier to clean around and often have a better wash and quieter operation.

Good if: you are refitting the bathroom or replacing the toilet anyway. Watch for: the cost of the frame, boxing-in, tiling and a new electrical supply inside the wall. Price the frame, connections and making good separately from the product.

Non-electric attachment

A thin plate that sits between your pan and your existing seat, with a lever-operated spray from the cold feed. There is no warm water, no heated seat and no dryer.

Good if: there is no power near the toilet, or you want to see whether you like washing before you spend more. Watch for: cold water, which many people find unpleasant in winter, and the same backflow rules as any other bidet.

Measure your toilet before you compare models

Person measuring a toilet pan with a tape measure from the seat fixing holes to the front edge of the bowl, with the old seat removed — Take the old seat off and measure the bare pan. Seat outlines hide the real bowl shape.

Retailers often say their seats fit "most UK toilets". That can be true and still not include yours. Before ordering a bidet seat, write down:

Fixing-hole spacing: the distance between the centres of the two seat bolt holes.
Bowl length: from the line between the fixing holes to the front edge of the rim. Round UK pans are often shorter than the elongated pans many seats are designed for.
Bowl width at the widest point.
Space behind the holes: from the fixing holes back to the cistern or wall. The seat's control unit sits here and needs room.
The rim shape: a flat rim is easiest. A sloping or very curved rim, or a pan with a built-in seat recess, may not suit.
Where the water isolation valve is, and which side of the toilet has space for the hose and cable.

Send the seller your numbers and a photo

A specialist retailer will usually confirm fit if you send your measurements and a picture of the pan from above and the side. Get the answer in writing. If they will not confirm, check the cancellation and return terms before opening or fitting it. Change-of-mind returns and rights for faulty or misdescribed goods are different; seller terms do not remove statutory rights. See GOV.UK guidance on returns.

For a complete smart toilet, the questions are different: do you have a suitable wall for a concealed frame, where does the soil pipe exit, and can power and water be run to the frame? That is a job for your installer to confirm on site. See installation and costs.

Use the bidet seat comparison by pan fit to build a shortlist. If you are considering a TOTO seat, the TOTO WASHLET model and pan-code guide explains its specific pairings.

Features worth paying for, and ones you can skip

Nearly every seat has more buttons than you will use. These matter most in daily use:

Adjustable water temperature, pressure and nozzle position. This is the core of the experience.
Continuous warm water (sometimes called instant or tankless heating) if more than one person will use it in a row. Tank-heated seats have a limited warm-water capacity; check the model documentation.
A self-cleaning nozzle you can remove or replace.
A heated seat with an energy-saving or timer mode, especially in a cold bathroom.
A remote with large, clear buttons, ideally wall-mounted, if anyone in the house has poor eyesight or grip.

Drying performance varies by model and user; try a demonstration if this feature matters to you. Automatic lids, night lights, app control and deodorisers are pleasant but rarely the reason to choose one model over another. Features explained in more detail.

Warranty, service and spare parts

A smart seat is an electrical appliance that lives in a wet room, so after-sales support matters more than on a normal toilet. Before buying, find out:

How long the warranty is on the electronics, not just the ceramic, and whether it covers labour.
Whether registration or a professional installer is needed to keep the warranty valid.
Who you contact in the UK if it stops working, and whether they send an engineer or ask you to post it back.
Whether filters, nozzles and remotes can be bought separately, and for how long.
The exact UK model number, voltage (230 V) and plug or connection type, especially on marketplace listings.

Questions to ask the seller before you order

Will this fit my pan? (Send the measurements above.)
What backflow protection does it have, and is it suitable under UK water regulations?
What power connection does it need, and how long is the cable?
What is included: T-valve, hose, fixing plate, remote bracket?
Can I return it if it does not fit, and in what condition?

Next: budget for the whole job

Once you know the type, check what the plumbing and electrical work is likely to cost, so the product price does not mislead you.

Installation and costs →

Before you buy: a smart toilet and bidet seat fit checklist