The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

  Names of Reporting Persons.

  Therese Tucker

  Check the Appropriate Box if a Member of a Group (See Instructions)

  (a)  ☐        (b)  ☒

  SEC Use Only

  Citizenship or Place of Organization

  Ms. Tucker is a U.S. Citizen

Number of

Shares

 Beneficially 

Owned by

Each

Reporting

Person

With:

  Sole Voting Power

  3,723,972¹

  Shared Voting Power

  1,179,118²

  Sole Dispositive Power

  3,723,972¹

  Shared Dispositive Power

  1,179,118²

  Aggregate Amount Beneficially Owned by Each Reporting Person

  4,903,090^1,2

  Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)

  Percent of Class Represented by Amount in Row (9)

  8.5%³

  Type of Reporting Person (See Instructions)

  IN

Consists of (i) 47,778 shares of Common Stock held by the Reporting Person; (ii) 5,808 shares of Common Stock issuable pursuant to restricted stock units that are subject to vesting conditions within 60 days of December 31, 2020; (iii) 217,504 shares of Common Stock subject to options which are exercisable within 60 days of December 31, 2019; (iv) 577,200 shares of Common Stock held by the Isaac Tucker 2012 Irrevocable Gift Trust; (v) 577,200 shares of Common Stock held by the Roseanna Tucker 2012 Irrevocable Gift Trust; and (vi) 2,298,482 shares of Common Stock held by the Brian & Therese Tucker Living Trust.

Consists of (i) 874,128 shares of Common Stock held by the Tucker Legacy Trust, dated 12/30/2014; (ii) 54,074 shares of Common Stock held by the Claire Seimetz 2015 Trust; and (iii) 250,916 shares of Common Stock held by the Tucker-Seimetz Safety Net Trust.

The percentage is calculated using 57,682,118 shares of Common Stock issued and outstanding as of December 31, 2020.

Item 1.

(a)

Name of Issuer: BlackLine, Inc.

(b)

Address of Issuer’s Principal Executive Offices: 21300 Victory Boulevard, 12th Floor, Woodland Hills, CA 91367

Item 2.

(a)

Names of Person Filing: Therese Tucker

(b)

Address of Principal Business Office or, if none, Residence: The principal business address of the Reporting Person is: 21300 Victory Boulevard, 12th Floor, Woodland Hills, CA 91367

(c)

Citizenship: Ms. Tucker is a U.S. Citizen

(d)

Title of Class of Securities: Common Stock

(e)

CUSIP Number: 09239B 109

Item 3.

If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

(a)

☐

Broker or dealer registered under Section 15 of the Act (15 U.S.C 78c).

(b)

☐

Bank as defined in Section 3(a) (6) of the Act (15 U.S.C 78c).

(c)

☐

Insurance Company as defined in Section 3(a) (19) of the Act (15 U.S.C 78c).

(d)

☐

Investment Company registered under Section 8 of the Investment Company Act of 1940 (15 U.S.C 80a-8).

(e)

☐

Investment Adviser in accordance with SS 240. 13d-1(b) (1) (ii) (E);

(f)

☐

Employee Benefit Plan or Endowment Fund in accordance with SS 240. 13d-1(b) (ii) (F);

(g)

☐

Parent Holding Company or Control Person in accordance with SS.SS.240. 13d-1(b) (ii) (G);

☐

A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

☐

A church plan that is excluded from the definition of an investment company under Section 3(c) (14) of the Investment Company Act of 1940(15 U.S.C 80a-3);

☐

Group, in accordance with SS 240. 13d-1(b) (1) (ii) (J);

Item 4. Ownership

Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

Amount beneficially owned: 4,903,090^1,2

Consists of (i) 47,778 shares of Common Stock held by the Reporting Person; (ii) 5,808 shares of Common Stock issuable pursuant to restricted stock units that are subject to vesting conditions within 60 days of December 31, 2020; (iii) 217,504 shares of Common Stock subject to options which are exercisable within 60 days of December 31, 2020; (iv) 577,200 shares of Common Stock held by the Isaac Tucker 2012 Irrevocable Gift Trust; (v) 577,200 shares of Common Stock held by the Roseanna Tucker 2012 Irrevocable Gift Trust; and (vi) 2,298,482 shares of Common Stock held by the Brian & Therese Tucker Living Trust.

Consists of (i) 874,128 shares of Common Stock held by the Tucker Legacy Trust, dated 12/30/2014; (ii) 54,074 shares of Common Stock held by the Claire Seimetz 2015 Trust; and (iii) 250,916 shares of Common Stock held by the Tucker- Seimetz Safety Net Trust.

The percentage is calculated using 57,682,118 shares of Common Stock issued and outstanding as of December 31, 2020.