Company: WBS-PG
Filing Date: 2025-09-05
Form Type: 424B5
Source: 0001193125-25-197211
Chunk: 21

Company: WEBSTER FINANCIAL CORP
Filing Date: 2025-09-05
Form: 424B5
Chunk 21
---
 levels. We have no control over a
number of matters, including, without limitation, economic, financial, and political events, that are important in determining the existence, magnitude and longevity of market volatility and other risks and their impact on the U.S. Treasury Rate for
a five-year maturity. In recent years, interest rates have been volatile, and that volatility may continue in the future.

The value of and return on the Notes may be adversely affected if the interest rate for the Subsequent Fixed Rate Period is determined using an alternative method or a replacement rate is used.

Under the circumstances described herein under “Description of Notes—Interest Rate,” the interest rate for the Subsequent
Fixed Rate Period will be determined using an alternative method to determine the applicable U.S. Treasury Rate or, if a Rate Substitution Event has occurred, using a Replacement Rate. If the interest rate for the Subsequent Fixed Rate Period is
determined by using such an alternative method or Replacement Rate, such alternative method or Replacement Rate may result in an interest rate and interest payments that are lower than or that do not otherwise correlate over time with the interest
rate and interest payments that would have been made on the Notes if the reset reference rate had been determined using the first method for determining the U.S. Treasury Rate for a five-year maturity specified under “Description of
Notes—Interest Rate.” If a Rate Substitution Event has occurred and it is determined there is no industry-accepted successor rate to the U.S. Treasury Rate for a five-year maturity, the interest rate for the Subsequent Fixed Rate Period
will be the interest rate for the Initial Fixed Rate Period.

The calculation agent will make determinations with respect to the Notes.

On the Reset Determination Date, the calculation agent will determine the interest rate for the period on and after the
Reset Date, as further described in this prospectus supplement. In addition, if the circumstances described herein under “Description of Notes—Interest Rate” or a Rate Substitution Event have occurred, the

S-11

calculation agent will make certain determinations with respect to the Notes in the calculation agent’s sole discretion as further described under “Description of the Notes—
Interest Rate.” Any of these determinations may adversely affect the payout to investors. Moreover, certain determinations made by us or our designee may require the exercise of discretion and the making of subjective judgments, such as with
respect to the occurrence or non-occurrence of a Rate Substitution Event. These potentially subjective determinations may adversely affect