Town hall bosses are "exasperated" at the time cuts-hit staff have to spend dealing with thousands of confusing emails from Whitehall, a public spending watchdog has said.
And they are also fed-up with rushed consultations on central government policies - most of which breach a code of practice and are timed during holiday periods.
An investigation by the National Audit Office (NAO) found there was a "high risk of waste" and project failure if local authority experience was not properly tapped.
And while most communications were of "good quality", the NAO concluded, bad practice was likely to be even more costly at a time when councils were being asked to do more with less cash.
In one month alone, March, authorities received 744,115 emails from Whitehall departments and their agencies - sending back 610,794 in the other direction. But some contained multiple links and "pages of unnecessary text", the NAO said, pointing the finger at the insufficient oversight of the standards of communications.
"Local authorities are exasperated by the poor signposting of some communications they receive from central government departments, which wastes the time of the hundreds of people who receive each one.
"This is a particular concern to local authority managers working with fewer staff following cost reductions, who therefore need to understand and act on communications more quickly.
"While the wasted time caused by a single poorly-designed communication to a single recipient may be small, the effect is multiplied where a communication is going to hundreds of local authorities, all repeating the same actions and thought processes to work out the message."
NAO head Amyas Morse said: "As the local delivery of services becomes an ever greater concern of central government, how departments and local government communicate with one another becomes all the more important.
"Communication and engagement between central and local government are inherently challenging, especially given the differences in priorities, ways of doing business and pressures. Communications need to be clear, timely and take account of these cultural differences."