Severance of joint tenancy: form A vs trust deed

[NickPrice]

Hello,

Wife owns 90%, I own 10% as joint tenants. We want to become tenants in common before sale to lessen CGT. There is a form A for this with the landregistry. Can a trust deed be used as well? How soon before selling should this change be affected?

Thanking you in advance.

[section 44]

Wife owns 90%, I own 10% as joint tenants.

No.

Perhaps:

Wife and you own the whole as joint tenants.

or Wife owns 90% and you own 10% as tenants in common.