Company registration number

Your business's unique identifier with the government authority that registered it. Every legitimate company has one. On WholesaleUp™, suppliers often require it before issuing a first quote — it proves you're a real business, not a consumer.

Tax ID (VAT / GST / EIN / TIN)

Your tax identifier for business-to-business transactions. In the EU and UK this is a VAT number; in the US a Federal Employer ID (EIN) or state Tax ID; in Australia an ABN. Suppliers use it to issue compliant invoices and, for intra-EU trades, to apply the reverse-charge mechanism.

Resale certificate / exemption certificate

A document that tells the supplier you are buying goods to resell (not consume), which exempts the transaction from local sales/use tax in some jurisdictions. US sales-tax states issue these; the UK/EU VAT system handles the same concept via reverse-charge instead.

Using a personal tax ID for a business purchase

Suppliers can't apply B2B tax treatment. You'll pay retail VAT/sales tax that you can't reclaim.

Claiming reverse-charge without a valid VAT number

Your supplier gets an audit finding. Most will refuse the order. Always verify your VAT registration is active in VIES before quoting it.

Submitting a resale certificate from the wrong state

US resale certificates are state-specific. A California certificate doesn't exempt Texas sales tax. Use a multi-state certificate where accepted.

Not registering for VAT while cross-border dropshipping

EU OSS/IOSS and UK post-Brexit rules make VAT registration necessary for smaller sellers than before. Check thresholds annually — they change.

Assuming a company number alone is enough

Registration proves incorporation. It doesn't prove tax status. Suppliers often want both the company number AND the tax ID.