How is Zakat on money paid from the mobile phone trade, which relies on credit purchases, achieves small profits, faces difficulties such as price decreases, and bears the burdens of operational expenses?

Phones, being trade goods, are subject to zakat just like other trade goods. At the completion of the hawl (one lunar year), their current market value is assessed. The amount equivalent to any outstanding debt is deducted from this value, and then zakat is paid on the remaining amount. Profit and loss are not considered as long as the remaining amount reaches the nisab (minimum taxable amount) by itself or when combined with other assets. If the remaining amount falls below the nisab, then no zakat is due.