Bank gaurantee for contarctor journal entry

By Bank Guarantee a/c

To Bank a/c

this is an asset and must be recognised as the bank guarantee could be in the form of an FD.

Any commission charges incurred

By Commission expenses a/c

To Bank A/c

If you complete the contract work and the FD will be returned to you and you can liquidate it

By Bank a/c

To Bank Guarantee a/c

If you cannot complete the work, then the FD will be impounded by the government

By Contract Loss a/c - P&L

By Bank Guarantee- SOFP

Now there is a need to create provision incase if your past experiences have bad remarks like onerous contracts. Here i think the possibility is remote and it is not required to disclose it in the statements as well.

Coming to your first question, when you close the ledger at the year end, the balance C/F will always be on the same side of the Dr or Cr column where the account is. Eg. Machinery account is an asset and a debit account/real account-

Debit The Receiver, Credit The Giver This principle is used in the case of personal accounts. ...
Debit What Comes In, Credit What Goes Out This principle is applied in case of real accounts. ...
Debit All Expenses And Losses, Credit All Incomes And Gains This rule is applied when the account in question is a nominal account

In the books of machinery being debit balance, usually the debit column will hold the C/F balance. This means debit balance, asset is carried forward to the next year. I couldnt find online examples for this.

If you want to carry forward balances, do it for all and add them up. It will give you the same debit and credit balance. I have attached a screenshot. Usually ledgers are closed.