| Document and Entity Information | Feb. 29, 2024 |
| Document and Entity Information [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Feb. 29, 2024 |
| 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 State Or Province | PA |
| Entity Address, Address Line One | 2301 Renaissance Blvd. |
| Entity Address, City or Town | King of Prussia |
| Entity Address, Postal Zip Code | 19406 |
| City Area Code | 800 |
| Local Phone Number | 355-3500 |
| Title of 12(b) Security | Class A common stock, $0.001 par value per share |
| Trading Symbol | VERX |
| Security Exchange Name | NASDAQ |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001806837 |
| Amendment Flag | false |
