The influential public accounts committee said the scale of losses from fraud and error was "staggering" and called for tougher enforcement action.
Parliament's spending watchdog urged Customs to investigate and prosecute more suspected fraudsters and speed up the legal process.
It also said detailed work was needed to find out how much non-compliance was deliberate and help target resources between education and enforcement.
Committee chairman Edward Leigh said: "A staggering '11 billion of VAT is being pocketed by fraudsters and cheats, rather than being collected for the public purse.
"Traders paying over the correct VAT and the taxpayer in general, will want to see Customs step up its efforts to tackle these losses.
"In particular, I urge Customs to consider tougher penalties for evasion and under-declaring VAT as a greater deterrent."
Mr Leigh, the Tory MP for Gainsborough, also said the forthcoming merger between Customs and the Inland Revenue should be exploited by sharing data on illicit trading.
The report found that: "The scale of VAT losses suggests that more investigations and prosecutions for all types of VAT fraud would be cost effective".
Investigations
Customs presently prosecuted around 90 VAT fraud cases each year and the number of investigations leading to civil penalties had fallen to 270 a year, it said.
But where it did not investigate a trader found to be under-declaring, the maximum penalty that could be levied was '15 of the value of the non-payment.
"Customs should analyse the level of repeat offending by traders to consider whether the number and level of penalties for under-declarations and for civil evasion should be raised to create a greater deterrent," the committee concluded.
Arrangements for speeding up complex fraud trials - which can presently take up to a year to prepare, needed to be agreed with the Department for Constitutional Affairs and put in place quickly, the MPs said.
They also called for more accountants, lawyers and tax advisers involved in the VAT under-declaration to be reported to their professional bodies.
That had only happened four times amid thousands of cases each year, they discovered.
"Customs should make greater use of such sanctions, working with the business community and professional bodies to agree criteria for reporting and the remedial action expected".
The report called for a timetable to be set for the training of investigators to external standards and for Customs to work with the European Commission on improving an EU-wide system designed to combat VAT fraud. Tweet

Comments
Login or Register to comment
who i am does not matter at this time, but ive had a stomach full of people defrauding vat and tax, this country gives the working class no incentives to be straight, it just takes we get less and the rich get more, there is no common denominator here only justice and both will have to suffer i am a builder and im not getting any work because im to good to expensive and to straight i frighten people, but its what they know about themselves that frightens them and what they think i know about them that makes them aggressive towards me, i would dearly love to be an independant vat and tax fraud agent there are literally hundreds of crooked people out there waiting to be prosecuted rich and poor alike
but my main concentration would be the large incorporate businesess which fiddle thousands each year for every one small poor fiddler i would take out one large rich company the ruling classess have a lot to answer for and they will all answer to the letter of the law