Explanation:

Rule of lapse: Rule of Lapse. Principle of Annuality also implies that the money left unspent in a year must also lapse to the public treasury and government should not be able to spend it unless it is re-sanctioned in next year's budget. This is called Rule of Lapse and is useful as an effective tool of financial control.
Supplementary Grant:  The additional grant required to meet the required expenditure of the government is called Supplementary Grants. Description: When grants, authorised by the Parliament, fall short of the required expenditure, an estimate is presented before the Parliament for Supplementary or Additional grants.
Vote on account: Since Parliament is not able to vote the entire budget before the commencement of the new financial year (like now, with elections round the corner), it is necessary to keep enough money at the disposal of government to allow it to run the administration of the country.