Supplementary Card (Additional Cardholder)
A supplementary card — also called an additional cardholder card — is a second credit card linked to your existing account that is issued to another person, typically a spouse, partner, or adult child. The supplementary cardholder gets their own physical card with their name on it, but all charges are billed to the primary cardholder’s account and count against the same credit limit. The primary cardholder is legally responsible for all purchases made on the supplementary card.
Adding a supplementary card is a common way for parents to help adult children establish a credit history, since the supplementary cardholder’s payment activity is typically reported to their credit bureau file as well.
Quick Facts
| Detail | Value |
|---|---|
| Canadian term | Supplementary card (US: “authorized user”) |
| Shares with primary | Same credit limit and account |
| Who’s responsible for charges | Primary cardholder, always |
| Credit reporting | Supplementary holder’s activity reported to their bureau |
| Supplementary card fee | $0 – $50/year (varies by card and issuer) |
| Age requirement | Typically 18+ (some issuers allow younger with conditions) |
| Number allowed | Usually 1–9 per account |
Canadian Context
In Canada, supplementary cardholders are sometimes called “authorized users,” but “supplementary card” is the term most commonly used by Canadian issuers. Unlike the US market, where supplementary card credit-building strategies are extensively documented, Canadian credit bureaus apply the benefit somewhat differently depending on the issuer — not all issuers report the supplementary holder’s activity to both Equifax and TransUnion. Before adding someone as a supplementary cardholder for credit-building purposes, confirm with the issuer which bureaus they report to. The primary cardholder bears full financial responsibility, so only add people you trust completely. Supplementary cardholder fees, where charged, typically grant the secondary holder access to the same travel insurance and card benefits as the primary holder.
Related Glossary Terms
Information on this page is provided for general educational purposes. Supplementary card policies, fees, and credit reporting practices vary by issuer — always confirm details directly with your card issuer.