Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Nov. 04, 2022
Document Information:
Document Type	10-Q
Document Period End Date	Sep. 30, 2022
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-39413
Entity Registrant Name	Vertex, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	23-2081753
Entity Address, Address Line One	2301 Renaissance Blvd
Entity Address, City or Town	King of Prussia
Entity Address State Or Province	PA
Entity Address, Postal Zip Code	19406
City Area Code	800
Local Phone Number	355-3500
Title of 12(b) Security	Class A Common Stock, Par Value $0.001 Per Share
Trading Symbol	VERX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Central Index Key	0001806837
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Amendment Flag	false
Class A
Document Information:
Entity Common Stock, Shares Outstanding		48,732,884
Class B
Document Information:
Entity Common Stock, Shares Outstanding		101,307,000