Company: QTIWW
Filing Date: 2025-02-05
Form Type: 424B3
Source: 0001628280-25-004061
Chunk: 424

Company: QT IMAGING HOLDINGS, INC.
Filing Date: 2025-02-05
Form: 424B3
Chunk 424
---
 months ended September 30, 2024 and 2023. The Company expects that its effective tax rate for the full year 2024 will be 0%.

<div align='center'>F-61</div>

#### QT IMAGING HOLDINGS, INC.

### Notes to Condensed Consolidated Financial Statements
<div align='center'>(Unaudited)</div>

#### 15.

#### Related Party Transactions

#### Convertible Notes Payable
In July 2020, the Company issued three convertible notes to three of its stockholders for advances up to $3,500,000 in principal (the “2020 Notes”) and bearing annual interest of 5% on any amounts drawn. An additional note was issued in March 2022 as part of the 2020 Notes, but with an annual interest rate of 8%. All principal and interest payments are due on or before July 1, 2025. The 2020 Notes are convertible, at the holder’s option, into shares of common stock of the Company at the lower of $14.59 per share or the offering price in a financing of at least $5,000,000 in equity from unaffiliated parties. As of September 30, 2024, an aggregate o f 250,224 s hares of common stock would be issued if the entire principal and interest under the 2020 Notes was converted. Management assessed whether the embedded features in the 2020 Notes should have been bifurcated from the debt host and concluded that none of the features were required to be accounted for separately from the debt instruments.

As of September 30, 2024 and December 31, 2023, the outstanding amount of the 2020 Notes was $3,143,725 and accrued interest of $507,029 and $377,772, respectively. Interest expense for the three months ended September 30, 2024 and 2023, was $43,400 and $45,921, respectively. Interest expen se for the nine months ended September 30, 2024 and 2023, was $129,257 and $136,265, respectively.

#### Working Capital Loan and Extension Note
On May 3, 2023, the Company issued a promissory note (the “Working Capital Note”) to a stockholder for a principal amount of $250,000. The Working Capital Note was subsequently amended and restated six times on June 12, 2023 to