Just looked up the EUs rules and it looks like Farage is the victim of a Torygraph slur (they must be worried).
For a start, it is an allowance paid monthly and not claimed as expenses. He does not have to produce receipts or invoices for his costs as it is a set rate paid to all MEPs. The General Expenditure Allowance is €4,299 per month and includes money for office cost. Farage is easily within that.
// General expenditure allowance
This allowance is intended to cover expenditure in the Member State of election, such as Members’ office management costs, telephone and postal charges, and the purchase, operation and maintenance of computer and telematics equipment. The allowance is halved in the case of Members who, without due justification, do not attend half the number of plenary sittings in one parliamentary year (September to August).
The amount of this allowance in 2011 is EUR 4 299 per month. //