For queries related to Registration and Returns
Commercial Taxes Department Help Desk Ground Floor, Vanijya Therige Karyalaya, Kalidasa Marg, Gandhinagar, Bengaluru - 560 009.
Head office toll free helpline - 18004256300 TDS Exclusive contact number at Head office- 080-22203247
Email id - ctd.gsthelpdesk@ka.gov.in
Division	District	Contact Number
Mangaluru	Udupi, Dakshina Kannada	1800-425-5581
Belagavi	Belagavi, Bagalakote, Vijayapura	1800-425-0320
Kalburagi	Raichur, Kalburagi, Yadgiri,Bidar	1800-599-0051
Dharwad	Dharwad, Haveri, Uttara Kannada, Gadag	1800-425-8490
Davangere	Davangere,Chitradurga,Bellary,Koppal	1800-425-0377
Malnad	Shivamogga, Chikamagaluru,Hassan	08182-295708
Mysuru	Mysuru, Chamrajanagar,Mandya, Kodagu	0821-2420360

For queries related to Deduction and Remittance under K2:
Khajane-II Helpdesk number: 9241300300 Khajane-II Helpdesk Whatsapp number:8050031331
Khajane-II Toll free number: 1800-425-4252
Email id - k2.helpdesk@karnataka.gov.in
Sl. No.	District	Contact Number
1	Bengaluru Rural	080-22129431
2	Bengaluru Urban	080-22275725
3	Bellary	8392277412
4	Chickballapur	8156272203
5	Chitraduga	08194222415
6	Davangere	8192257922
7	Kolar	08152222016
8	Ramanagara	27271320
9	Tumakuru	8162278498
10	Mysuru	0821 – 2423351
11	Chamaraj Nagar	8226222339
12	Chickmangaluru	0826-2232085
13	Hassan	8172268404
14	Madikeri	08272225654
15	Mandya	8232225415
16	Mangaluru	08242220575
17	Udupi	8202523130
18	Shivamogga	8182279788
19	Belagavi	8312422050
20	Dharwad	8362448251
21	Gadag	08372237477
22	Haveri	08375249071
23	Vijayapura	8352250199
24	Bagalakote	8354235721
25	Uttara Kannada (Karwar)	08382226369
26	Hubballi	08362350219
27	Bidar	08482226203
28	Kalaburgi	8472221937
29	Yadgiri	08473253711
30	Koppala	08539220577
31	Raichur	08532228330

For further details- Visit the nearest Local GST office (LGSTO/SGSTO) in your district.