The UK Phonics Screener is a very simple test, that does not involve any reading skills other than recognising a small group of high-frequency graphemes and blending them. A child who speaks no English can learn to recognise the graphemes and blend them - without knowing what they mean. Many are 'nonsense' words, and test just those skills - with words that do not have meaning, even if you speak English. 

Without phonemic awareness children can recognise the graphemes (say a sound when they look at a letter) but may struggle to say the word. So any test should really isolate skills, and be more useful as a diagnostic tool. At the moment it is really just used to record what teachers can tell you about the child already. In many ways, the test is to assess the teacher, to see if they are systematically teaching that specifically set of graphemes. You can see them above, in the 4 SSP Code Levels, however, there are 350+ in 'real' text, and so this stage is really just to introduce children to the concept of decoding and encoding - within meaningful context (or as much as it can be with a limited number of graphemes, and a few hundred high-frequency words)

We have to tell our children to ONLY map the graphemes to the phonemes in the 4 Code Levels. Otherwise, because we are exploring the WHOLE code, they want to give all combinations- especially with these pseudo words. For example they know the letter /t/ can represent several speech sounds (not just t as in tap)make!) and /a/ can represent at least 8 speech sounds, the letter /s/ can represent several also.
So if shown tas as a pseudo word, they would want to see how many ways the word could be pronounced!
Instead, we have to tell them to limit the choices to those covered in the 4 code levels. So children who are well on their way to 'orthographic mapping' can struggle with the limitations of this test, and especially at the end of year 1 - our aim is to have the children reading by then, and exploring the whole code during word study activities. We would prefer to do this test at the end of the first year of school, if mandatory. The real test, however, is that of PHONEMIC AWARENESS in term 1. This enables teachers to identify and address the reasons why most children fail the UK phonics test in non SSP (Speech Sound Pics Approach) other classrooms. An early intervention is far better. There is no reason, if the child has no intellectual impairment, why they aren't reading by 6. So why does it take so many children so long? The instruction does not cater for their individual needs (the focus in on teaching, rather than learning - and not fully differentiated)

So if you want to help your child pass the UK phonics test that is actually really easy, with the resources we supply. You can then test them at home with PAST UK PHONICS SCREENING TESTS on this page. 
To be able to read age-appropriate chapter books with fluency and comprehension is far more complex, but very much 'sped up' when a speech-to-print approach is taken, and with SPELLING activities as a major focus each day. Use the 30 Minute Constrained Skills routine and the children will be able to pass the UK Phonics Screener at the end of Reception. They are learning at THEIR pace. Differentiation is key.