public function getStatus(): ?string
    {
        // Active when no expiration intent
        if (null === $this->expiration_intent) {
            return $this::STATUS_ACTIVE;
        }

        // Pending when retrying
        if ($this::RETRY_PERIOD_ACTIVE === $this->is_in_billing_retry_period) {
            return $this::STATUS_PENDING;
        }

        // Expired when not retrying
        if ($this::RETRY_PERIOD_INACTIVE === $this->is_in_billing_retry_period) {
            return $this::STATUS_EXPIRED;
        }

        return null;
    }