A supplementary credit card is an extra card on your own credit card account, issued to a family member or someone you trust. It draws on your credit limit, its spending appears on your statement, and you as the principal cardholder are ultimately liable for every charge. The holder must be at least 18, under MAS’s card regulations, unless the card is for overseas travel.
This guide explains how supplementary cards work, who is liable, the minimum ages and the fees, from MAS’s regulations, the Association of Banks in Singapore’s Code of Practice and the banks’ own terms, as at November 2026.
The short version: A supplementary card is convenient for a spouse, parent or grown-up child, but it is your debt. Set a sub-limit where your bank allows one, and treat their spending as your own.
How a Supplementary Credit Card Works
You, the principal cardholder, apply on the other person’s behalf. At DBS, the main cardholder starts the application in the digibank app and the supplementary applicant completes it in their own app. Standard Chartered asks the principal to submit the form with both people’s identity documents.
The supplementary holder gets their own card, in their name, linked to your account. MAS’s regulations count supplementary cards within the principal’s credit limit, so their spending reduces what you have available. DBS lets you choose a preferred credit limit for the supplementary card when you apply.
Rewards normally go to the principal. UOB says UNI$ earned on supplementary cards build up in the principal’s account and only the principal can redeem them. HSBC says supplementary card spending earns cashback on its cards.
The supplementary holder does not need to meet the income test. MAS’s minimum income rule applies to the principal, and the regulations exempt a supplementary card where the bank has already checked the principal. Read our guide to credit card minimum income for that rule.
Who Is Liable for a Supplementary Card
The Association of Banks in Singapore’s Code of Practice for Banks on credit cards says banks must tell both cardholders their respective liabilities and remind the principal “that he is ultimately liable for charges incurred by his supplementary cardholder(s)”.
DBS’s Credit Card Agreement spells out how that works:
- The principal is liable for all amounts on the account, whether incurred by the principal or the supplementary cardholders, and is jointly and severally liable with each supplementary cardholder for their card’s share.
- The supplementary cardholder is liable only for the part of the balance from their own card.
In practice, the bank can pursue you for the whole bill, and the supplementary holder for their part. If the bill is not paid in full, interest of 27.8% to 27.9% a year applies at the main banks, as our guide to how credit card interest works explains.
If a supplementary card is lost or stolen, the same S$100 cap on liability for unauthorised charges applies as on the principal card, provided you report it promptly and were not negligent.
Minimum Ages and Fees at the Main Banks
MAS’s card regulations bar banks from issuing a supplementary card to anyone under 18, except where the card is needed for overseas travel, and then only for a limited period. The banks we checked require principal cardholders to be at least 21.
| Bank | Supplementary holder minimum age | Supplementary annual fee (example) |
|---|---|---|
| DBS | 18 | S$98.10 a card on the Altitude card |
| UOB | Not stated on the pages we checked | First supplementary card free, second S$98.10 on Absolute Cashback |
| Citibank | Not stated in the pricing guide | S$98.10 on Cash Back+ and Rewards; free on PremierMiles |
| HSBC | 18 | Free for life, up to five cards |
| Standard Chartered | 18 | Free for life, per its application form |
| CIMB | 18 | No annual fee on principal or supplementary cards |
Figures from each bank’s own page, form or fee schedule, including GST, as at November 2026. Fees differ by card, so check the card you hold.
Worked Example: A Card for a Child at University
Illustration only. A parent adds a supplementary card for a 19-year-old studying locally, with a $500 sub-limit, on a card charging $98.10 a year for each supplementary card.
- The child spends $400 a month on transport, books and meals. That is $4,800 a year on the parent’s account.
- Paid in full each month, the cost is the $98.10 fee, and the parent collects any rewards.
- If one month’s $400 is left unpaid, it attracts interest at about 27.8% a year from the purchase dates, plus a $100 late fee if the minimum is missed, all charged to the parent’s account.
For a teenager, a debit card linked to their own savings account may be the simpler choice. Our comparison of debit card vs credit card sets out the differences.
Before You Add or Keep a Supplementary Card
- Agree how it will be paid. The bank only deals with the principal on the bill.
- Use a sub-limit if the bank offers one. It caps how much the card can run up.
- Check the fee each year. Some supplementary fees are waived only in the first year.
- Remove it when it is no longer needed. Contact the bank to cancel the supplementary card.
What To Do Next
- Read the supplementary card section of your bank’s cardholder agreement, and the fee on its fee page.
- Decide on a sub-limit and how the supplementary holder will repay you.
- Check whether your card’s rewards are worth sharing; the cashback vs miles calculator helps compare.
- If you are choosing a new card with family use in mind, see our best credit cards in Singapore page and the full card table.
