Can I ask for a change to the agreement before I sign?
Yes — there's a request-a-change option on a pending agreement, so you don't have to choose between signing it as-is and refusing outright.
A pending agreement has an option to raise a free-text change request. Describe what you'd like changed and why. Your landlord is emailed and it appears on their tenancy page.
If they agree, they amend the clauses or the addendum and send a fresh version, which automatically cancels the old one — so there's never more than one live document. If they don't, they can tell you and the original stands.
Worth knowing: Raising a request doesn't sign anything and doesn't commit you. Nothing takes effect until you actually sign.
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Not legal advice
These answers describe how Tenarize works and summarise the law in England as the product implements it. They are not legal advice about your situation, and the law changes. For free independent help, Citizens Advice and Shelter both cover renting in England; for anything unusual or contested, take advice from a solicitor.
Tenarize does not currently support Scotland, Wales or Northern Ireland, whose tenancy regimes are different.