Angie,
Under the requirements in 1026.9(c)(1) you must provide notice 15 days prior to the effective date of the change on a home equity line. But the rules in 1026.40 do not allow changes to HELOC unless certain conditions exist. Section 1026.40(f)(3)(iii) allows a change if the consumer agrees to the change.
So instead of just providing a notice of change, provide the customer with a notice explaining the change and obtain the consumer’s consent (signature) agreeing with the change.