There is no format prescribed for an invoice, however, Invoice rules makes it mandatory for an invoice to have following fields (only applicable field are to be filled):

(a) name, address and GSTIN of the supplier;

(b) a consecutive serial number, in one or multiple series, containing alphabets or numerals or special characters hyphen or dash and slash symbolised as “-” and “/” respectively, and any combination thereof, unique for a financial year;

(c) date of its issue;

(d) name, address and GSTIN or UIN, if registered, of the recipient;

(e) name and address of the recipient and the address of delivery, along with the name of State and its code, if such recipient is unregistered and where the value of taxable supply is fifty thousand rupees or more;

(f) HSN code of goods or Accounting Code of services;

(g) description of goods or services;

(h) quantity in case of goods and unit or Unique Quantity Code thereof;

(i) total value of supply of goods or services or both;

(j) taxable value of supply of goods or services or both taking into account discount or abatement, if any;

(k) rate of tax (central tax, State tax, integrated tax, Union territory tax or cess);

(l) amount of tax charged in respect of taxable goods or services (central tax, State tax, integrated tax, Union territory tax or cess);

(m) place of supply along with the name of State, in case of a supply in the course of inter-State trade or commerce;

(n) address of delivery where the same is different from the place of supply;

(o) whether the tax is payable on reverse charge basis; and

(p) signature or digital signature of the supplier or his authorized representative