Hosting means putting your data on someone else's computer. It is worth being precise about what that gives them, because both common assumptions. That they see nothing, and that they are reading everything, are wrong.
What they can technically reach
Every file in your account. Administrative access to a server includes the file system. Your code, your uploads, your configuration files including database passwords.
Every database. In full, including customer records.
Every mailbox. Including the messages in it. This is the one that surprises people most, and it is the plainest consequence of hosting your own mail. Where email should live explains the wider decision.
Server logs. Which addresses requested which pages, when.
None of this is a flaw. It is what makes support, migrations and recovery possible. A provider who could not read your files could not restore them.
What they cannot read
Anything that was made unreadable before it reached the server.
A password stored properly. Passwords in a well-built application are stored as irreversible hashes. Nobody can read them, including your provider and including you.
Data your application encrypted with a key held somewhere else. If the key is on the same server, this is weaker than it sounds, but a key held elsewhere genuinely puts the data beyond reach.
The distinction that matters: permissions do not protect you from an administrator; encryption does. No file permission stops root.
What a good provider does with that access
Uses it when there is a reason, and records the reason.
Accessing an account to resolve a ticket you raised is normal. Doing so without a reason is not, and the difference is policy and culture rather than technology, because the technical capability is identical either way.
Which is why on a shared server the provider's staff practices matter more than any control you can apply yourself.
What it means for sensitive data
If your site holds data whose exposure would be serious, health information, financial records, anything you are legally responsible for; the storage should not be the only protection.
Encrypt those fields in the application, with a key that is not on the same machine. Then a compromise of the server, by anyone, does not disclose them.
This is worth doing regardless of provider, because it also covers the scenarios that have nothing to do with them: a compromised site, a stolen backup, a disk that left the building. Server hardening goes into that last one.
The password question
A hosting provider does not need your password to help you. A reseller opens your control panel from their own; a host has server access already.
So a request for your password is a signal. It usually means the request is not really from your provider, and it is a very common form of the fake support message.
A legitimate provider will occasionally ask you to grant temporary access through a documented mechanism, which is different and traceable. Opening cPanel from WHM without a password deals with what your provider actually uses.
Legal requests
A provider can be compelled to hand over data, and that applies wherever the servers are.
Worth knowing rather than worrying about: it is a reason to understand which jurisdiction your data sits in if that matters to your business, and a reason not to treat any hosting arrangement as private from every party.
What to actually do
Choose a provider whose practices you are willing to rely on, since the technical access is a given.
Keep your own backups somewhere else, so your recovery does not depend on them. For that, see managing backups.
Encrypt what genuinely needs it, in the application.
And keep your account secure at your end, because the most likely disclosure is not your provider; it is a reused password on your own login. Securing your hosting account explains that side.
What is recorded about visitors, not just about you
The access log holds every visitor's address, the pages they requested and when. That is personal data in most jurisdictions, and it sits on the provider's machine by default.
Which makes two things worth knowing. Retention is a setting rather than a law of nature, logs kept for a year are a year of visitor history you are responsible for. And the provider has the same access to it as you do.
If your privacy notice describes what you collect, the server's own logging is part of that answer whether or not anyone mentioned it. There is more on the obligations that follow in what a website needs for privacy compliance.
Backups extend the reach
Everything the provider can see now, they can also see in every backup they hold, for as long as they hold it.
That matters in a specific way: data you delete from the live site persists in backups until those rotate out. A customer record removed on request is genuinely gone from the site and present in last night's copy.
Ask what the retention is, and whether deletion requests are honoured in backups or only in the live data. Most providers do the latter, which is normal and is worth knowing rather than assuming. Managing WordPress backups sets out the copies you control.
Shared hosting has neighbours
The provider is not the only other party on the machine.
On a shared server, other accounts run code on the same hardware. Proper isolation prevents them reading your files, and what they share is the address, the mail reputation and the resources, which is why a neighbour's compromise can affect your mail deliverability without touching your data.
That is a different exposure from the provider's access and it is worth distinguishing: one is a trust question, the other is a technical boundary that occasionally fails.
Where the data genuinely cannot tolerate a shared machine, that is the argument for a VPS rather than for a different provider. Comparing hosting tiers walks through what changes.
What to ask, in writing
Four questions, answered before they matter.
Where are the servers, and where is the company registered. How long are backups kept. Under what circumstances do staff access an account, and is it logged. What happens to the data if the account is closed or the company changes hands.
A provider that answers these plainly is telling you something; one that will not is telling you something else. Neither answer is a technical detail. They are the terms on which you are relying on them. What to ask before moving to a new host sets out the rest of that conversation.