Can I pay my brother to build my website? Does this have tax implications for him if one time 500$ job

The cost of paying someone to build a website for your business is typically deductible as an ordinary and necessary business expense under IRC §162. This applies whether the person is a family member or not. The expense is deductible in the year it is incurred, provided it is directly related to your business. However, your brother must report the $500 as income on his tax return, as it constitutes taxable income. If your brother is not in the business of building websites, he would report this on his Form 1040 as 'Other Income'. If he is in the business of providing such services, he should report it on Schedule C. It's important to treat this transaction as you would with any other vendor, including issuing a Form 1099-NEC if you pay him $600 or more during the year.