Kitchens are usually cheaper to tile than bathrooms of the same size, for the simple reason that there is far less wall to cover.
What gets tiled
In a modern kitchen the tiled area is typically the strip between the worktop and the wall units, plus a splashback behind the hob and sink. Base units cover the wall below the worktop and wall units cover much of the wall above.
MyJobQuote puts a splashback above a sink at half a day, £75 to £100.
A run of upstand tiling between worktop and wall units across a kitchen is more, but it is still a modest area, often only three to five square metres.
Floor tiling is the bigger element in most kitchens, and it is priced on the room's footprint at the standard labour rate of roughly £20 to £40 per square metre.
Why the labour rate sits higher than the area suggests
Kitchen tiling is cut-heavy. The tiled strip runs around sockets, switches, extractor outlets, window reveals and the edges of units, and every one of those is a cut.
Cutting takes far longer than laying whole tiles, and cuts around a socket have to be accurate because they are at eye level and directly lit. So a small kitchen area can take a surprising amount of time relative to its square metreage, and the per-square-metre rate reflects that.
This is worth knowing when comparing a kitchen quote against a bathroom quote. Fewer metres does not mean proportionally fewer hours.
The substrate question
Kitchen walls are frequently painted, and tiling over paint is risky because the tiles bond to the paint rather than the wall. Gloss and vinyl silk in particular need abrading and priming, or removing.
The area behind a hob may also have specific requirements depending on the appliance, and glass or metal splashbacks are sometimes a better answer than tile there.
Kitchen floors take heavier traffic and more dropped objects than most rooms. Porcelain is generally a better choice than ceramic for a kitchen floor, and the substrate needs to be sound and rigid, because a floor that flexes cracks tiles and grout.
In an older South London property with suspended timber floors, floor tiling usually needs an overlay board or a decoupling membrane first. That is an extra layer of cost and one of the most common omissions from a cheap quote.
Sequencing
Tile after the units are fitted and the worktop is in, not before. The tiled strip is measured from the worktop up, and tiling first means cutting to fit whatever the units turn out to be.
Floor tiling is the exception and is often done before units go in, so the floor runs continuously underneath. That matters if you might reconfigure the kitchen later, and it also affects appliance heights, since an integrated dishwasher sitting on tile has less clearance than one on bare floor.
Decide this with whoever is fitting the kitchen before the tiler is booked.
Grout choice
Kitchens are messier than bathrooms in a different way. Grout behind a hob or sink takes grease, cooking splashes and repeated cleaning.
A darker grout hides staining far better than white, and an epoxy grout, while harder to work with and more expensive, is effectively stain-proof and worth considering behind a hob.