Generally speaking, Yr 1 is too young to judge if there is a underlying problem or if it's purely maturity related.
Is you child a summer born? That alone could account for a lot - at that age a few months make a massive difference with regards to maturity. In most European countries, kids aren't even at school at this age. Many are just not ready/interested developmentally and expectations are too high for such young children.
That said, if there are physical problems like eyesight or hearing (e.g. glue ear), things will get worse if not addressed. So it would be very wise to eliminate that as the first step.
With regards to the rest, is he generally doing OK developmentally? E.g. can he concentrate on a task that interests him (i.e. not school work) or does he get distracted easily? How is his speech and verbal comprehension (i.e. non written)? Can he follow multi-step instructions? Is his vocabulary vivid and well-developed? Can he retell stories/tell you about something that happened in a coherent fashion? Is he generally alert/interested/intelligent? Does he like logic puzzles/problem-solving (i.e. not maths worksheets)? If all of the above checks out, I would say you can safely assume that his maths and reading difficulties are a maturity thing and you can afford to wait until at least mid-year 2 (having eliminated physical issues) before getting worried/getting EdPsych report done.
If things don't improve by mid-year 2, I would do an assessment by a good EdPsych to make sure there are no issues such as dyslexia/working memory/processing issues etc. Mid-year 2 is not too late even if an assessment reveals issues, you'll have plenty of time to resolve things before secondary.
Even if a report doesn't show issues you'll know where he stands on the IQ scale and you'll know what your starting point is.
Regardless of the outcome though, approach suggested by Fernando is the right one. Regardless of the diagnosis (or lack thereof), remedial actions are the same. Lots of on going, well-structure, little and often support using multi-sensory methods. It's hard work and you just have to make time for it and this work every time. I am afraid it's difficult to outsource unless you can shell out thousands for various (well-qualified!) tutors to come in 3-4 times a week. I am afraid one hour per week to do "fun" school work won't work - neither for resolving maturity issues nor more serious ones (if any).
There are plenty of resources to make things fun and multisensory (
http://www.ldalearning.com for example), tips on Internet, Mumsnet and this forum. It's just a lot of hard work and not a quick fix.
