Govt. has issued notifications 68/2019 to 72/2019 – Central Tax, Dated 13th December, 2019, which are related to E-Invoicing under GST.  Summary of all these notifications is as mentioned below –

Notification No. & Date of issueSubjectSummary
Notification No. 72/2019-Central Tax ,dt. 13-12-2019Seeks to notify the class of registered person required to issue invoice having QR Code.QR Code on B2C Invoice
is mandatory for registered person, whose aggregate turnover in a financial year exceeds five hundred crore rupees (>500 crores)
w.e.f 1st April, 2020
Notification No. 71/2019-Central Tax ,dt. 13-12-2019Seeks to give effect to the provisions of rule 46 of the CGST Rules, 2017.Applicability of Rule 5 of CGST (Fourth Amendment), 2019 made vide notification No. 31/2019 – Central Tax, dated the 28th June, 2019 “Tax invoice shall have Quick Response (QR) code.”
w.e.f 1st April, 2020
Notification No. 70/2019-Central Tax ,dt. 13-12-2019Seeks to notify the class of registered person required to issue e-invoice.E-Invoice is mandatory for registered person, whose aggregate turnover in a financial year exceeds one hundred crore rupees (>100 crores)
w.e.f 1st April, 2020
Notification No. 69/2019-Central Tax ,dt. 13-12-2019Seeks to notify the common portal for the purpose of e-invoice.Electronic Invoice Portal
(i) http://www.einvoice1.gst.gov.in;
(ii) http://www.einvoice2.gst.gov.in;
(iii)www.einvoice3.gst.gov.in;
(iv) http://www.einvoice4.gst.gov.in;
(v) http://www.einvoice5.gst.gov.in;
(vi) http://www.einvoice6.gst.gov.in;
(vii) http://www.einvoice7.gst.gov.in;
(viii) http://www.einvoice8.gst.gov.in;
(ix) http://www.einvoice9.gst.gov.in;
(x) http://www.einvoice10.gst.gov.in.
w.e.f  1st January, 2020
Notification No. 68/2019-Central Tax ,dt. 13-12-2019Seeks to carry out changes in the CGST Rules, 2017.Insertion of Sub-rules 4, 5 & 6 in Rule 48 of GST Rules, 2017 (Regarding issuance of Invoice). E-Invoice should contain the particulars as mentioned in FORM GST INV-01 w.e.f 13th December, 2019