This usually indicates that an active discount has expired and the subscription is now being charged at the regular rate. If you'd like to double-check, please see your latest billing invoice or reach out to our care team via chat or on 0808 234 5337 (8 am - 7 pm M-F, free from UK mobile & landlines) so we can review the billing for you. 🙂
Your discounted rate is expired and you have to pay the regular rate now. Open a new blank QBO account with the same email address to pay the discounted rate again.