Who told you that? Nonsense.
You can apply for probate as little as 7 days after death. However, to apply for probate you will need a proper valuation of the estate (assets and liabilities) which can take a couple of weeks to obtain from the asset holders/creditors.
You must wait 6 months from the Grant of Probate to distribute in case there is a claim under the Inheritance (Provision for Family and Dependants) Act 1975. If you distribute within this period and there is a claim, the executors can be personally liable.
There is also the 3 month period under the Trustee Act notices (these are normally published in the London Gazette and one local paper saying "if you are a creditor, please come forwards in 3 months"). Legally the execs do not have to do this, but it protects them personally from claims by a creditor (although it does not protect the beneficiaries) who comes forwards after this time if the appropriate notices are place.
In respect of funeral expenses see here
http://www.hmrc.gov.u...manual/ihtm10375.htm. However, they must be reasonable according to the deceased's station in life (ie a famous pop star may end up with a more extragavent wake that Mrs Joe Bloggs). HMRCS are unlikely to allow a great lash up though!