Foundation courses

As someone who's taken all science subjects at A-level, can i do a foundation course in buisness and economics after Alevels and then apply for another university with my alevel grades while doing the foundation course? Also, can you mention that ur doing a foundation course in economics in ur personal statement and will that be treated the same way as an Economics A level? I'm currently considering this pathway as I regret applying for biochemistry and want to do economics but I don't want to take a gap year, and self-learning an Alevel seems to be very difficult.

Eh?

For business degrees, you don't need any specific subjects just so long you have the right grades. If anything, the general grade requirements for business school related degrees tend to be lower than that for science subjects. Business A Level is not a required subject.
The only area in business where you would need a specific subject would be finance, and there you need A Level Maths (further maths might not be necessary, but there is an offchance the top end universities might ask for it in their finance courses because of how mathematical they are).

For economic degrees, you have 2 types: quantiative and nonquantitative. The nonquantiative requires no specific subjects, just the right grades. The quantiative degrees will at least require A Level Maths (some might ask for Further Maths on top). You won't need A Level Economics to go into the degree.
If you want to do a foundation year in economics, your A Levels should be more than enough so long the grades are high enough. See the following as examples:
https://www.mdx.ac.uk/courses/undergraduate/economics-foundation-year
https://www.kent.ac.uk/courses/undergraduate/5799/economics-foundation-year
https://www.essex.ac.uk/courses/ug00103/4/bsc-economics
https://www.surrey.ac.uk/undergraduate/economics/2023#entry
https://www.london.ac.uk/courses/bsc-economics#entry-requirements-19591 (for various degrees in London universities - it's a network of universities)

I can't see you ever really needing to do a foundation year in business; but you will likely need it for a degree in economics. Should you ever do one, make sure you do it at the university where you want to do your business/economics degree. It would be difficult to switch universities after you have done your foundaiton year, since each foundaiton year course is tailored to the specific university that it's taught at.

I personally find doing the A Level as a private candidate more convenient and not particularly difficult (at least it's not as bad as say chemistry, but to each his own). It's also significantly cheaper (£1000 including course fees, should you take a course on it) than a foundation year (£9250).

By the way, business economics is not the same thing as straight economics or business. It's economics with a business context and it's usually easier than a straight economics degree (so you might be able to skip the A Level Maths requirement, if you're lucky).
Financial economics is similarly somewhat different, but it's slightly more mathematical than business economics. I have not seen the need to use calculus in financial economics, but I might be wrong.

More to the point, what do you intend to do after your degree? If there's no specific career you want in economics, then there's not much point fussing over which degree in social science you end up doing. A degree in economics only offers you the advantage of becoming an economist or go into economics research (you're not likely going to need it anywhere else, including jobs in finance).
If you intend to work in a role in business, you won't likely even need a degree. The entry requirement for most business roles is just to show up and be competent. For pickier roles such as those in accounting and finance would require you to have specific professional qualifications suited for those particular roles - the entry requirements for these are generally A Levels in any subject, except for actuary where you will likely need A Level Maths.
If you want specific qualifications that would help you move up the corporate ladder quicker, there are usually professional qualifications that you can go for in marketing, HR, law, etc. The entry requirements for these qualifications is next to nothing if you start off at Level 3, but you can get exemptions for Level 3 and 6 if you have a suitable degree in the subject.
You won't need anything to start your own business, should you wish. However, I wouldn't recommend starting a business out of the blue with no background or experience. You will need the business knowledge and a craft, but you won't need to go through academia to get them.
If you intend to go into business research, you can do an MBA or MSc/MA in a business subject prior to doing your doctorate, and the entry requirements for these degrees are generally undergrads in any subject so long you have the right grade (MBA might ask for GRE/GMAT score and relevant managerial work experience)

Wow reli warms my heart so see such a detailed response ty. Basically, I've received offers for biochem but now am thinking that Id be more interested and happier doing Management Bsc. I dont reli want to take a gap year and was wondering if doing a foundation year would be a better choice as I have zero knowledge of economics and buisness which r the fundementals of a mangement degree. I am looking at Bath/Warwick's international foundation year as I still need 2 years to qualify as a British citizen hence I can apply for that. My parents have told me that theyre willing to fund me for the foundation year if i wish to do it(i do consider myself very lucky to not have to worry about student finance). Yes, I know i could do biochem and switch to buiness or sth else later but I just dont have any passion for sciences and I do want to make my uni life interesting. What do you say? should I do it?