Amphibians of the UK
There are six, arguably 7 amphibian species native to the UK. Three of these are members of the order Caudata (the salamanders) with the remaining 4 belonging to Anura (the frogs and toads).
The three salamanders, or newts as we often refer to them, are: The smooth newt (Lissotriton vulgaris), the Palmate newt (Lissotriton helveticus) and the Great crested newt (Triturus cristatus).
The three species of Anura that are definitely native to the UK are the Common frog (Rana Temporaria), the Common toad (Bufo bufo) and the Natterjack toad (Epidalea calamita). The fourth native species is the Northern Pool frog (Pelophylax lessonae). This species became extinct in 1995 but was re-introduced to several sites in East Anglia between 2005-2008.
In the UK there are lots of amphibian species living wild that are not native to these isles. The majority of these are species that are or have been common in the pet trade. Their wild populations are the result of deliberate or accidental releases. The species that have been recorded living in the wild in the UK include: The Marsh frog (Pelophylax ridibundus), the Edible frog (Pelophylax esculentus), the America Bull frog (Lithobates catesbeianus), the Midwife toad (Alytes obstetricans) and the Alpine newt (Ichthyosaura alpestris). These are only a few of the naturalised species and there are many others living wild in the UK. Some of these populations are recorded, however there are many others that are probably not.
In the UK there are only the two orders of amphibians, however in South america, Africa and southern Asia there is a third: Gymnophiona.
Here is a video on how to identify the frogs and toads of the UK