Chargebee currently supports certificates whose root certificate is from any of the following Certificate Authorities (CA). You can also cross-check your certificate installation at Qualys SSL Labs.
AAA Certificate Services
AddTrust Class 1 CA Root
AddTrust External CA Root
AddTrust Qualified CA Root
America Online Root Certification Authority 1
America Online Root Certification Authority 2
Baltimore CyberTrust Code Signing Root
Baltimore CyberTrust Root
Certum CA
Certum Trusted Network CA
Chambers of Commerce Root
Chambers of Commerce Root - 2008
Class 1 Public Primary Certification Authority
Class 2 Primary CA
Class 3P Primary CA
Class 3 Public Primary Certification Authority
COMODO RSA Certification Authority
Deutsche Telekom Root CA 2
DigiCert Assured ID Root CA
DigiCert Global Root CA
DigiCert High Assurance EV Root CA
DST Root CA X3 - (LetsEncrypt) CA
Entrust.net Certification Authority (2048)
Entrust.net Secure Server Certification Authority
Entrust Root Certification Authority
Entrust Root Certification Authority - G2
Equifax Secure Certificate Authority
Equifax Secure eBusiness CA-1
Equifax Secure Global eBusiness CA-1
GeoTrust Global CA
GeoTrust Primary Certification Authority
GeoTrust Primary Certification Authority - G3
GeoTrust Universal CA
Global Chambersign Root - 2008
GlobalSign
GlobalSign
GlobalSign Root CA
Go Daddy Class 2 Certification Authority
GTE CyberTrust Global Root
GTE CyberTrust Root 5
KEYNECTIS ROOT CA
QuoVadis Root CA 2
QuoVadis Root CA 3
QuoVadis Root Certification Authority
Security Communication EV RootCA1
Security Communication RootCA1
Security Communication RootCA2
Sonera Class1 CA
Sonera Class2 CA
Starfield Class 2 Certification Authority
Starfield Secure Certificate Authority - G2
StartCom Certification Authority
SwissSign Gold CA - G2
SwissSign Platinum CA - G2
SwissSign Silver CA - G2
TC TrustCenter Class 2 CA II
TC TrustCenter Class 4 CA II
TC TrustCenter Universal CA I
Thawte Personal Freemail CA
Thawte Premium Server CA
thawte Primary Root CA
thawte Primary Root CA - G3
Thawte Server CA
Thawte Timestamping CA
Trustwave Organization Validation SHA256 CA
T-TeleSec GlobalRoot Class 2
T-TeleSec GlobalRoot Class 3
UTN - DATACorp SGC
UTN-USERFirst-Client Authentication and Email
UTN-USERFirst-Hardware
UTN-USERFirst-Object
ValiCert Class 1 Policy Validation Authority
ValiCert Class 2 Policy Validation Authority
VeriSign Class 1 Public Primary Certification Authority - G3
VeriSign Class 2 Public Primary Certification Authority - G3
VeriSign Class 3 Public Primary Certification Authority - G3
VeriSign Class 3 Public Primary Certification Authority - G5
VeriSign Class 1 Public Primary Certification Authority - G2
VeriSign Trust Network
VeriSign Universal Root Certification Authority