(a) Concurrently with each report, the employer shall pay to the department the amount of contributions imposed by this act for the period covered by the report; but the department may, in proper cases, upon request made, permit an extension of time for the payment of contributions due. The amount of the contribution in respect of which an extension is granted shall be paid (with interest at the rate of one-half of one per centum per month), or fraction of a month, on or before the expiration of the period of extension.

(b) For the purposes of this act, contributions due by an employer with respect to wages for employment under this act (i) which have been paid as contributions required under another state or Federal unemployment compensation law and (ii) which have been subsequently credited to the account of such employer under this act, shall be deemed to have been paid into the Unemployment Compensation Fund as of the date payment thereof was made under such other state or Federal unemployment compensation law.

(c) Whenever the secretary shall determine that the collection of any contributions under the provisions of this act will be jeopardized by reason of the fact that the employer is insolvent or has discontinued business at any of its known places of business or the business is temporary or seasonal in nature, he may immediately assess such contributions, together with all interest and penalties which may have accrued whether or not the date otherwise prescribed for the filing of reports or for making payment of such contributions has arrived. Such contributions, interest and penalties shall thereupon become immediately due and payable and notice of demand shall be made upon the employer for the payment thereof.