Cyber hackers have targeted a housing association serving central and south west England.
Bromford has some 40,000 homes in the region but its chief information officer said there was no evidence the hackers had been successful.
Earlier this week, the housing association announced it had shut down its systems as a precaution
The chief executive said: "Returning to normal can only happen when we know our systems are safe."
The organisation provides services for about 90,000 people, according to the Local Democracy Reporting Service.
Chief information officer Dan Gooddsall said: "As a precaution we have shut down all of our technology, this includes the systems which tell us which appointments we have, the systems we use to communicate with customers and the systems we use to interact with our suppliers.
"This means that we are only taking emergency calls on the main Bromford number but you can still make payments using our automated phone line.
"And you can still contact your neighbourhood coach by phone or text.
"We know how much of a pain this must be and we are so sorry for missed appointments and how limited our service is," he added.
Bromford's chief executive, Robert Nettleton, gave an update on Thursday to assure customers there was no evidence of a data breach.
He thanked all customers, suppliers and partners for their patience and understanding and said: "We are now working to return to normal in a safe and controlled manner".
"Please remember that all our neighbourhood coaches, our income colleagues, and support workers are here to help you and work with you," he added.
Gloucester City Council faced months of disruption to services after it was targeted by Russian-linked hackers.
The cyber attack cost the taxpayer hundreds of thousands of pounds and some of its services have yet to be fully restored.
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