If the subscription is no longer active or trialing, sender seats stop licensing. Senders may show a No seat badge until the card is fixed. No seat is a license badge, not a sender status.
What you see
Billing status can read Past due or Canceled. Only Active and Trialing license seats.
Open Settings → Billing → Plan and read Status.
If senders exceed licenses, Billing names how many are not sending, for example "{N} senders are not sending. Choose a plan to license seats."
Open Senders. Extra senders keep a No seat badge. The badge title is "Not sending: no licensed seat."
Owner or admin selects Manage billing and updates the card, or starts a plan again on Plan.
Account Protection blocks sends from unlicensed senders. Unibox does not send. Add sender stays blocked at capacity with "No seats left. Delete a sender or choose a plan with more seats."
Fix the card, then wait for license
Update the payment method in Stripe. When the subscription is active or trialing again, seats license and the No seat badge clears for senders inside the quantity. Teammates stay free the whole time. Monthly tokens do not roll over. Pack tokens you already bought do not expire.
Do not delete a sender unless you want a smaller seat count. Deleting frees a seat. It is not required to retry a card.