| Document and Entity Information | Aug. 09, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Aug. 9, 2021 |
| Entity Registrant Name | Paymentus Holdings, Inc. |
| Entity Central Index Key | 0001841156 |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity File Number | 001-40429 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 45-3188251 |
| Entity Address, Address Line One | 18390 NE |
| Entity Address Address Line2 | 68TH ST. |
| Entity Address, City or Town | Redmond |
| Entity Address, State or Province | WA |
| Entity Address, Postal Zip Code | 98052 |
| City Area Code | 888 |
| Local Phone Number | 440-4824 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Class A Common Stock, $0.0001 par value per share |
| Trading Symbol | PAY |
| Security Exchange Name | NYSE |
