BT, Britain's biggest broadband and mobile operator, laid out the impact of COVID-19 today, with earnings forecast to drop by up to 9% this year reflecting the impact of the virus on its small and large business customers.
CEO Philip Jansen said BT had helped keep Britain going during the height of the pandemic.
He said the company handled a 20% jump in daytime data as millions worked and schooled at home.
The first quarter was "relatively resilient" in challenging circumstances, Jansen said, with both revenue and core earnings falling 7% after it offered credit to its BT Sport customers when matches were canceled and enterprises delayed projects.
Jansen said BT, which pulled its dividend in May to help weather the pandemic, now had enough visibility to provide guidance for the year.
"Despite our strong operational performance in the first three months of the year, it is clear that Covid-19 will continue to impact our business as the full economic consequences unfold," he said.
BT said it expected to produce adjusted core earnings of between £7.2 billion and £7.5 billion for its 2020/21 financial year on revenue down between 5% and 6%.
"These financial results and our outlook for the rest of the year demonstrate that BT is a resilient business in a resilient sector," Jansen said. "We have worked tirelessly since the start of lockdown to help the country stay connected."
Analysts had expected full-year earnings of about £7.5 billion on revenue down 5.6%, according to a company-compiled consensus.
BT said today that its coverage would remain unaffected by the government's decision to phase out China's Huawei from Britain's 5G network.
Prime Minister Boris Johnson this month reversed his decision in January to allow China's controversial technology leader to roll out Britain's fast new data network.
He banned new 5G equipment purchases from January and told operators to strip out existing gear plugged into the nascent system by the end of 2027.
Boris Johnson said the step was a response to new US sanctions on Huawei and not a consequence of diplomatic pressure put by Washington in its standoff with Beijing.
Johnson also did not require companies to remove Huawei equipment from 4G and older networks - something BT had warned would take a decade and billions of pounds to do.
And he gave full-fibre broadband providers until 2029 to remove the Chinese tech.
BT said in a trading update that the cost of Johnson's reversal to the company fell "within previously reported estimate" of £500m.
"Further work required to comply with additional restrictions on the use of Huawei equipment but no anticipated impact on coverage or rollout of 5G and full fibre," BT said in a report to the London Stock Exchange.
BT's mobile operator EE used Huawei equipment at the core of its main 4G network.
Some of that equipment was used to switch consumers with new phones from 4G to 5G when the speedier version began being introduced in Britain last year.
But BT has also signed a deal with Sweden's Ericsson for a new core network that could replace Huawei's in the coming years.