SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Accel X LP (Last) (First) (Middle) 500 UNIVERSITY AVENUE (Street) PALO ALTO CA 94301 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol Slack Technologies, Inc. [ WORK ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 06/11/2019
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	06/11/2019		C		3,705,529	A	$0(1)	3,705,529	I	By Accel Growth Fund III L.P.(2)
Class A Common Stock	06/11/2019		C		174,942	A	$0(1)	174,942	I	By Accel Growth Fund III Strategic Partners L.P.(3)
Class A Common Stock	06/11/2019		C		245,497	A	$0(1)	245,497	I	By Accel Growth Fund Investors 2014 L.L.C(4)
Class A Common Stock	06/11/2019		C		1,219,420	A	$0(1)	1,219,420	I	By Accel Growth Fund IV L.P.(5)
Class A Common Stock	06/11/2019		C		6,937	A	$0(1)	6,937	I	By Accel Growth Fund IV Strategic Partners L.P.(6)
Class A Common Stock	06/11/2019		C		58,325	A	$0(1)	58,325	I	By Accel Growth Fund Investors 2016 L.L.C.(7)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Class B Common Stock	(1)	06/11/2019		C		3,705,529		(1)	(1)	Class A Common Stock	3,705,529	$0(1)	11,116,587	I	By Accel Growth Fund III L.P.(2)
Class B Common Stock	(1)	06/11/2019		C		174,942		(1)	(1)	Class A Common Stock	174,942	$0(1)	524,827	I	By Accel Growth Fund III Strategic Partners L.P.(3)
Class B Common Stock	(1)	06/11/2019		C		245,497		(1)	(1)	Class A Common Stock	245,497	$0(1)	736,492	I	By Accel Growth Fund Investors 2014 L.L.C.(4)
Class B Common Stock	(1)	06/11/2019		C		1,219,420		(1)	(1)	Class A Common Stock	1,219,420	$0(1)	3,658,260	I	By Accel Growth Fund IV L.P.(5)
Class B Common Stock	(1)	06/11/2019		C		6,937		(1)	(1)	Class A Common Stock	6,937	$0(1)	20,812	I	By Accel Growth Fund IV Strategic Partners L.P.(6)
Class B Common Stock	(1)	06/11/2019		C		58,325		(1)	(1)	Class A Common Stock	58,325	$0(1)	174,973	I	By Accel Growth Fund Investors 2016 L.L.C.(7)

1. Name and Address of Reporting Person* Accel X LP (Last) (First) (Middle) 500 UNIVERSITY AVENUE (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Accel Growth Fund III L.P. (Last) (First) (Middle) 500 UNIVERSITY AVENUE (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Accel Growth Fund III Strategic Partners L.P. (Last) (First) (Middle) 500 UNIVERSITY AVENUE (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Accel Growth Fund III Associates L.L.C. (Last) (First) (Middle) 500 UNIVERSITY AVENUE (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Accel Growth Fund Investors 2014 L.L.C. (Last) (First) (Middle) 500 UNIVERSITY AVENUE (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Accel Growth Fund IV L.P. (Last) (First) (Middle) 500 UNIVERSITY AVENUE (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Accel Growth Fund IV Strategic Partners L.P. (Last) (First) (Middle) 500 UNIVERSITY AVENUE (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Accel Growth Fund IV Associates L.L.C. (Last) (First) (Middle) 500 UNIVERSITY AVENUE (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Accel Growth Fund Investors 2016 L.L.C. (Last) (First) (Middle) 500 UNIVERSITY AVENUE (Street) PALO ALTO CA 94301 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. Each share of Class B Common Stock is convertible without payment or consideration into one share of Class A Common Stock at the option of the holder and has no expiration date.

2. These shares are held by Accel Growth Fund III L.P. Accel Growth Fund III Associates L.L.C is the general partner of each of Accel Growth Fund III L.P. and Accel Growth Fund III Strategic Partners L.P. (together, the "Accel Growth Fund III Entities). The managing members of Accel Growth Fund III Associates L.L.C. are Andrew G. Braccia, Sameer K. Gandhi, Ping Li, Tracy L. Sedlock, Ryan Sweeney, and Richard P. Wong. Accel Growth Fund III Associates L.L.C. has sole voting and dispositive power with regard to the shares held by the Accel Growth Fund III Entities, and its managing members share such powers.

3. These shares are held by Accel Growth Fund III Strategic Partners L.P. Accel Growth Fund III Associates L.L.C. is the general partner of each of the Accel Growth Fund III Entities. The managing members of Accel Growth Fund III Associates L.L.C. are Andrew G. Braccia, Sameer K. Gandhi, Ping Li, Tracy L. Sedlock, Ryan Sweeney, and Richard P. Wong. Accel Growth Fund III Associates L.L.C. has sole voting and dispositive power with regard to the shares held by the Accel Growth Fund III Entities, and its managing members share such powers.

4. These shares are held by Accel Growth Fund Investors 2014 L.L.C. The managing members of Accel Growth Fund Investors 2014 L.L.C. are Andrew G. Braccia, Sameer K. Gandhi, Ping Li, Tracy L. Sedlock, Ryan Sweeney, and Richard P. Wong, all of whom share voting and dispositive power with regard to the shares held by Accel Growth Fund Investors 2014 L.L.C.

5. These shares are held by Accel Growth Fund IV L.P. Accel Growth Fund IV Associates L.L.C. is the general partner of each of Accel Growth Fund IV L.P. and Accel Growth Fund IV Strategic Partners L.P. (the "Accel Growth Fund IV Entities"). The managing members of Accel Growth Fund IV Associates L.L.C. are Andrew G. Braccia, Sameer K. Gandhi, Ping Li, Tracy L. Sedlock, Ryan Sweeney, and Richard P. Wong. Accel Growth Fund IV Associates L.L.C. has sole voting and dispositive power with regard to the shares held by the Accel Growth Fund IV Entities, and its managing members share such powers

6. These shares are held by Accel Growth Fund IV Strategic Partners L.P. Accel Growth Fund IV Associates L.L.C. is the general partner of each of the Accel Growth Fund IV Entities. The managing members of Accel Growth Fund IV Associates L.L.C. are Andrew G. Braccia, Sameer K. Gandhi, Ping Li, Tracy L. Sedlock, Ryan Sweeney, and Richard P. Wong. Accel Growth Fund IV Associates L.L.C. has sole voting and dispositive power with regard to the shares held by the Accel Growth Fund IV Entities, and its managing members share such powers.

7. These shares are held by Accel Growth Fund Investors 2016 L.L.C. The managing member of Accel Growth Fund Investors 2016 L.L.C. are Andrew G. Braccia, Sameer K. Gandhi, Ping Li, Tracy L. Sedlock, Ryan Sweeney, and Richard P. Wong, all of whom share voting and dispositive power with regard to the shares held by Accel Growth Fund Investors 2016 L.L.C

Remarks:

This Form 4 is the second of three Form 4s filed relating to the same event. Combined, the three reports report the holdings for the following reporting persons (the "Accel Reporting Persons"): Accel X L.P., Accel X Strategic Partners L.P., Accel X Associates L.L.C., Accel Investors 2009 L.L.C., Accel XI L.P., Accel XI Strategic Partners L.P., Accel XI Associates L.L.C., Accel Investors 2013 L.L.C., Accel Growth Fund III L.P., Accel Growth Fund III Strategic Partners L.P., Accel Growth Fund III Associates L.L.C., Accel Growth Fund Investors 2014 L.L.C., Accel Growth Fund IV L.P., Accel Growth Fund IV Strategic Partners L.P., Accel Growth Fund IV Associates L.L.C., Accel Growth Fund Investors 2016 L.L.C., Accel Leaders Fund L.P., Accel Leaders Fund Associates L.L.C. and Accel Leaders Fund Investors 2016 L.L.C. This Form 4 has been split into three filings because there are more than 20 Accel Reporting Persons in total, and the SEC's EDGAR filing system limits a single Form 4 to a maximum of 10 reporting persons. Each Form 4 is filed by designated filer Accel X L.P.

	/s/ TRACY L. SEDLOCK. ATTORNEY IN FACT	06/12/2019
	** Signature of Reporting Person	Date
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