How to keep an account for my iPhone business?

Hello I'm 17 and I need some help keeping an account for my new business. I buy broken iPhones, refurbish them and sell them on for a profit but I'm not sure how to set out an account for this as I was never the best at accountancy. Please could someone help me out? Would be very much appreciated!

You just need a record book (with bound pages, not a ring binder or spiral bound).

Make a note of the date of each sale or purchase, how much it was and what it was - buying a phone or parts, selling a phone etc., and who /what company the transaction was with.

That's all you need as a minimum.

It's a good idea to have a separate bank account for the business and put everything through it. That gives you another record of everything to cross check the books with & prove they are accurate if you ever get audited.

You need to tell your local tax office (HMRC) that you are self employed. They will send you a tax form once a year; if you fill it in quickly enough, just about all you have to put in is the totals of your sales, purchase & expenses and they will do the rest of the calculations for you.

You don't actually pay any tax until you get to around £9000 a year profit / income (if you have another job as well), but you still need to declare what you earn.

Don't forget National Insurance either - it's only around £2.20 per week for self employed, but you need to pay for something like 90% of your working life to get full government benefits when you retire.