How do I combine subscriptions

Question

I have a new computer. How do I combine the complementary 365 subscription with the one I currently have?

Answer 1

A Microsoft account can have only one active Microsoft 365 for home subscription at a time, so subscriptions are not “combined” in parallel. Instead, adding another eligible subscription either extends time on the current plan or switches the plan type.

How the complimentary subscription works depends on what it is and what you already have:

1. If the complimentary offer is the same type as your current subscription (for example, both are Microsoft 365 Family):
   • Redeem the new subscription using the same Microsoft account as the existing one.
   • Any remaining time on the current subscription is added to the new one (up to a 5‑year maximum).
   • Example: 6 months left on Microsoft 365 Family + 12‑month Family offer = 18 months total.
2. If the complimentary offer is Microsoft 365 Personal and the current subscription is Microsoft 365 Family:
   When redeeming the Personal offer on the same account, there will be a choice:
   • Stay with Microsoft 365 Family:
     • The remaining Family time is converted and added to the new Personal subscription, but because Family costs more, less than a full year of time may be added.
   • Switch to Microsoft 365 Personal:
     • The account moves to Personal and can no longer be shared with others.
     • Remaining Family time is converted and added to Personal according to Microsoft’s conversion rules.
3. If the complimentary offer is Microsoft 365 Family and the current subscription is Microsoft 365 Personal:
   • Redeem the Family subscription with the same Microsoft account.
   • The account is upgraded to Family and the remaining Personal time is converted and added to the Family subscription.
   • Family can then be shared with up to five other people.
4. If the complimentary offer came with the new computer and is Microsoft 365 Personal, but there is a desire to keep the existing Family subscription unchanged:
   • Either:
     • Redeem the offer now on a different Microsoft account, or
     • Wait until the current subscription expires, then redeem the complimentary Personal offer on the main account.

Key limits and notes:

• Only one active Microsoft 365 for home subscription per Microsoft account at a time.
• Adding another subscription extends time, not device limits or storage per user.
• Total subscription duration on a single account cannot exceed 5 years; attempting to exceed this can cause a Redemption Failed error.

To actually apply the complimentary subscription, redeem its product key/offer using the Microsoft account that should own the subscription, then follow the on‑screen choices about staying on the current plan or switching.

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References:

• What happens if I add another Microsoft 365 for home subscription to my account?
• Try or buy Microsoft 365