9. Intangible Assets and Goodwill

Acquired intangible assets subject to amortization consist of the following (in thousands):

As of March 31, 2026, the weighted average remaining useful life for customer relationships was 11.1 years, developed technologies was 1.2 years, trademarks and trade names was 5.8 years, and capitalized software development costs was 0.5 years.

Amortization expense for customer relationships intangible assets is included in sales and marketing expenses and totaled $848 and $501 for the three months ended March 31, 2026 and 2025, respectively. Amortization expense for developed technologies intangible assets is included in cost of software solutions revenue and totaled $154 and $182 for the three months ended March 31, 2026 and 2025, respectively. Amortization expense for trademark and trade name intangible assets is included in general and administrative expenses and totaled $20 and $23 for the three months ended March 31, 2026 and 2025, respectively. Amortization expense for capitalized software development costs is included in general and administrative expenses and totaled $102 and $0 for the three months ended March 31, 2026 and 2025, respectively.

As of March 31, 2026, annual amortization of definite lived intangible assets, based on existing intangible assets and current useful lives, is estimated to be the following (in thousands):

The following table provides a summary of changes in the carrying amounts of goodwill (in thousands):