"Obviously it's a concern because our chief business cost on a day-to-day basis is fuel. I think we're headed for pretty tough times ahead," Allis said.
He added at least 50% of the calls he receives are requests for quotes, as customers compare his pricing with other services, such as Uber.
"We're under a continual pressure to lowball ourselves and do prices we were doing 15 years ago, even though fuel prices are at an all time high," he said.
"It's just a complete nightmare in that respect."
Susannah Moffat, who runs Ledbury Road Services in Tewkesbury, Gloucestershire, said "the last thing we want is to lose more trade" by putting the prices up.
"The only thing we can do is keep cutting our margin, time and time again, to try and keep the price increases to a minimum," she said.
Moffat said the petrol station was now "relying" on income from shop sales instead.
"It's a difficult business to be in at the moment. Seems like there's no end in sight really, but hopefully it won't be forever," she added.
Meanwhile, volunteer blood bike charity Freewheelers, which supports the NHS by delivering lifesaving medical products, said they are "sucking up the impact in our reserves".
The organisation covers an operational distance of more than 220,000 miles (354,055 km) per year across Bristol, Somerset, Bath and west Wiltshire.
"We've spent £17,000 on fuel per year over the last couple of years," said Chris MacDonald, chair of the Bristol branch.
"This current year it's heading towards £22,000, so it's a significant jump."
The charity relies solely on public fundraising, and said if fuel prices continue to rise, they would have to reduce the number of "low priority" callouts.
"But we're not there yet. We can sustain the current situation for a while by digging into our reserves," MacDonald assured.
Extracted and lightly reformatted for readability. · Source: pt