How to Activate a Giffgaff SIM Card

Activating a Giffgaff SIM is a quick online process — no phone calls, no forms in the post. You'll need your SIM card (with its 6-digit activation code), an email address, and a payment method for your first top-up or goodybag.

Step 1: Find your activation code

Your Giffgaff SIM card has a 6-digit activation code printed on the plastic card it came attached to (and usually on the SIM itself). If you ordered a SIM free online it arrives by post in 3-5 working days. Don't have one yet? Order a free Giffgaff SIM here.

Step 2: Go to the activation page

Head to giffgaff.com/activate in any browser — or download the giffgaff app and tap "Activate SIM". Enter your 6-digit code.

Step 3: Register your account

Enter your email address and pick a member name and password — this becomes your giffgaff login for managing your account, topping up and getting support. This is the "registration" step people search for: the SIM and the account are created together in one flow.

Step 4: Top up or choose a goodybag

Activation requires a payment — either:

• £10 top-up — pure pay as you go credit. New members who joined via a referral link (like ours) get £5 bonus credit free with their first top-up.
• A goodybag from £6 — a 30-day bundle of data, unlimited calls and texts. Best value if you use your phone daily.

Not sure which? Start with the £10 top-up — you can always buy a goodybag from your credit later.

Step 5: Insert the SIM and you're live

Pop the SIM into any unlocked phone. It normally connects to the O2 network within minutes — look for signal bars and try a test text. No signal? Restart the phone once; that's usually all it takes.

Keeping your old number

Activate the SIM with its new number first, then transfer your old number afterwards:

• Text PAC to 65075 from your old SIM to get your switching code.
• In your giffgaff account, go to "Transfer my number" and enter the PAC.
• Your number moves across within one working day, and your old SIM stops working automatically.

Full walkthrough in our PAC code switching guide.

Activation problems? Quick fixes

• Code not accepted: check for 0 vs O mix-ups, and that the SIM is a genuine giffgaff SIM.
• Phone says "SIM not valid": your phone is probably locked to another network — contact that network to unlock it (usually free).
• No signal after activation: restart the phone, check you're in an O2 coverage area, and give it up to 24 hours.
• Still stuck: message a giffgaff agent via your account's Help section — see our Giffgaff customer service guide.