Can I write off Google Ads if my website earns affiliate commissions?

Generally, yes. If your affiliate website is operated as a real business, Google Ads used to promote that site are typically deductible as an advertising or marketing expense.

Key points:

• The ads should be ordinary and necessary for the affiliate business.
• The campaigns should relate to the site or affiliate offers, not personal use.
• You should report affiliate commissions as income.
• The ad cost is usually deducted as a business expense against your business income; it is not a dollar-for-dollar tax credit.
• In the U.S., if you operate as a sole proprietor or single-member LLC, advertising expenses are commonly reported on Schedule C.
• If the activity is treated as a hobby rather than a business, deductions may be limited or unavailable.

Keep records such as Google Ads invoices, payment receipts, campaign details, landing pages promoted, affiliate-network reports, and bank/payment records showing commissions received.

Tax treatment depends on your country, business structure, and whether the site is genuinely run for profit, so check the rules that apply to you or ask a tax professional.