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		17,146,080	A	$0(1)	17,146,080	D
Class A Common Stock	06/11/2019		C		1,286,873	A	$0(1)	1,286,873	I	By Accel X Strategic Partners L.P.(2)
Class A Common Stock	06/11/2019		C		688,373	A	$0(1)	688,373	I	By Accel Investors 2009 L.L.C(3)
Class A Common Stock	06/11/2019		C		3,649,641	A	$0(1)	3,649,641	I	By Accel XI L.P.(4)
Class A Common Stock	06/11/2019		C		274,210	A	$0(1)	274,210	I	By Accel XI Strategic Partners L.P.(5)
Class A Common Stock	06/11/2019		C		387,596	A	$0(1)	387,596	I	By Accel Investors 2013 L.L.C.(6)

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		17,146,080		(1)	(1)	Class A Common Stock	17,146,080	$0	51,438,240	D
Class B Common Stock	(1)	06/11/2019		C		1,286,873		(1)	(1)	Class A Common Stock	1,286,873	$0	3,860,617	I	By Accel X Strategic Partners L.P(2)
Class B Common Stock	(1)	06/11/2019		C		688,373		(1)	(1)	Class A Common Stock	688,373	$0	2,065,117	I	By Accel Investors 2009 L.L.C(3)
Class B Common Stock	(1)	06/11/2019		C		3,649,641		(1)	(1)	Class A Common Stock	3,649,641	$0	10,948,923	I	By Accel XI L.P.(4)
Class B Common Stock	(1)	06/11/2019		C		274,210		(1)	(1)	Class A Common Stock	274,210	$0	822,630	I	By Accel XI Strategic Partners L.P.(5)
Class B Common Stock	(1)	06/11/2019		C		387,596		(1)	(1)	Class A Common Stock	387,596	$0	1,162,788	I	By Accel Investors 2013 L.L.C.(6)

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 X STRATEGIC PARTNERS 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 X 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 Investors 2009 L.L.C. (Last) (First) (Middle) 500 UNIVERSITY AVE. (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 XI L.P. (Last) (First) (Middle) 500 UNIVERSITY AVE. (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 XI 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 XI Associates L.L.C. (Last) (First) (Middle) 500 UNIVERSITY AVE (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 Investors 2013 L.L.C. (Last) (First) (Middle) 500 UNIVERSITY AVE. (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 X Strategic Partners L.P. Accel X Associates L.L.C. is the general partner of each of the Accel X Entities. The managing members of Accel X Associates L.L.C. are Andrew G. Braccia, Kevin J. Efrusy, Sameer K. Gandhi, Ping Li, Tracy L. Sedlock, and Richard P. Wong. Accel X Associates L.L.C. has sole voting and dispositive power with regard to the shares held by the Accel X Entities, and its managing members share such powers.

3. These shares are held by Accel Investors 2009 L.L.C. The managing member of Accel Investors 2009 L.L.C. are Andrew G. Braccia, Kevin J. Efrusy, Sameer K. Gandhi, Ping Li, Tracy L. Sedlock, and Richard P. Wong, all of whom share voting and dispositive power with regard to the shares held by Accel Investors 2009 L.L.C.

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

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

6. These shares are held by Accel Investors 2013 L.L.C. The managing members of Accel Investors 2013 L.L.C. are Andrew G. Braccia, Sameer K. Gandhi, Ping Li, Tracy L. Sedlock, and Richard P. Wong, all of whom share voting and dispositive power with regard to the shares held by Accel Investors 2013 L.L.C.

Remarks:

This Form 4 is the first 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 10 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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