question about taxes

As I understand (though I'm not a tax expert) you need to pay taxes on the profit which you make on the sale of these items.

Translation of what tax agency says on this matter:

Tax rules on sale

An activity shall be taxed in any of the income capital, business or service. It is important that taxation takes place in the right income category, as this is important for the treatment of deficits and social security contributions. When assessing the income type of the business, one looks at three criteria:

- independence
- duration and duration
- profit purpose.

If all three criteria are fulfilled, ie the business is run independently, sustainably and for profit, it should be taxed in the income category business.

Individual sales of, for example, a purchased board, a photo collection, a stamp collection or the like shall be taxed in income capital.

If the business is not taxed in any of the income classes of business or capital, it is on duty.

thank you. I saw on their website that one needs to pay taxes if he or he makes more than 25000 or 28000 kr on the tax year. Is that right? And what happens if we don't have the receipts of the original items that we bought, but we know the original price - do we pay taxes on the profit (difference between the original price and sold one) or do we pay taxes on the sales price?

One needs to pay taxes if income is more than 18800 SEK per year. But the tax or moms are on the price of the items. My understanding is that is separate from "income". I think it would be good for you if you visit skatteverket office and seek advice from them. There is also a helpline but it might be a bit complicated to discuss over phone. Better to visit the tax office with a sample case in your mind. Bought an item for 100 SEK, want to sell it for 100 SEK profit. What is correct way to do? How much tax to pay and how to pay?

Reading the tax office guidelines, i think if you do this regularly, it might be considered as a business activity and then the tax rules are in another dimension.

Thank you for the explanation. That is very kind of you. I don't want to make a business out of it, and since this is not my job, I would prefer to avoid anything that can put me in trouble.
It is not difficult to generate a lot of transactions when you buy online things like professional equipment, or even books and personal items. Used equipment is many times defective and we have to return it or sell it again. Photographic lenses cost between 1000 and 10000 SEK, so, if I have to buy a few it will reach the limit straight away. Sometimes, even if you buy and return them, they still count as cash movements, at least on PayPal. Not sure about the Bank.
I also find it ecological to sell online items that you don't use anymore, like books, school materials, equipment, etc. It produces a lot of waste.
But, you are right, better to stay informed!