Can I claim Amazon products I bought before launching my site?

Yes, possibly — but it depends on what you mean by “claim.”

If you mean claiming them as business expenses for your website, items bought before launch may be claimable if they were bought for a genuine business purpose, such as product testing, photography, reviews, comparison content, or other site-related work. Keep receipts, record when and why you bought each item, and separate business use from personal use. Depending on your country’s tax rules, pre-launch costs may be treated as startup costs, inventory, equipment, or regular expenses, so the timing and deductibility can vary.

If you mean claiming Amazon affiliate commissions, usually no. Amazon Associates commissions generally require a qualifying purchase through your active affiliate link, and they are not normally paid retroactively for purchases made before your links/site were active. Purchases you make yourself also generally do not qualify for affiliate commissions.

If you mean reviewing products you bought before launching the site, yes — you can usually review products you already own, provided your content is honest and you include any required affiliate or advertising disclosures.

Check the current Amazon Associates rules for your region and your local tax rules before relying on this. If it is for taxes, consider asking a qualified tax professional.