Company: OIA
Filing Date: 2025-03-06
Form Type: POS EX
Source: 0001193125-25-048456
Chunk: 2

Company: Invesco Municipal Income Opportunities Trust
Filing Date: 2025-03-06
Form: POS EX
Chunk 2
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| ☐ | If an Emerging Growth Company, indicate by check mark if the registrant has elected not to use the extended                                       
 transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of Securities Act. |

| ☐ | New Registrant (registered or regulated under the Investment Company Act for less than 12 calendar months 
 preceding this filing).                                                                                   |

EXPLANATORY NOTE

This Post-Effective Amendment No. 1 to the Registration Statement on Form N-2 (File Nos. 333-283796 and 811-05597) of Invesco Municipal Income Opportunities Trust (as amended prior to the date hereof, the “Registration Statement”) is
being filed pursuant to Rule 462(d) under the Securities Act of 1933, as amended (the “Securities Act”), solely for the purpose of filing certain exhibits to the Registration Statement. Accordingly, this Post-Effective Amendment No. 1
consists only of a facing page, this explanatory note, Part C of the Registration Statement and exhibits h(ii), e and s filed pursuant to Item 25 of the Registration Statement. This Post-Effective Amendment No. 1 does not modify any other part
of the Registration Statement. Pursuant to Rule 462(d) under the Securities Act, this Post-Effective Amendment No. 1 shall become effective immediately upon filing with the Securities and Exchange Commission. Parts A and B of the Registration
Statement are hereby incorporated by reference.

PART C

OTHER INFORMATION

Item 25. Financial Statements And Exhibits

| (1) |     | Contained in Part A: |

Financial Highlights of the Invesco Municipal Income Opportunities Trust (the “Registrant”) for the last ten fiscal
years and for the fiscal period ended August 31, 2024.

Registrant’s Financial Statements for the fiscal years ended February 29, 2024,
February 28, 2023, February 28, 2022, February 28, 2021 and February
29, 2020, are incorporated in Part A by reference to Registrant’s February29, 2024 Annual Report (audited) on Form N-CSR as filed with the U.S. Securities and Exchange Commission (the “SEC” or the “Commission”) via EDGAR Accession No. 0001193125-24-129060 on May 2, 2024.

Registrant’s Financial