This paper presents and analyzes two different strategies for designing multiformat online decimal adders ($\text{olDFA}_{\text{Mformat}}$). The first strategy uses a code conversion stage plus an online Decimal Full Adder (olDFA); the second one involves designing specific adders by modifying the architecture of the olDFA. These strategies are applied in the design of specific architectures to deal with financial analysis calculations. We use synthesis results to verify the theoretical aspects of the designs and to analyze the robustness and lacks of the strategies. The guidelines presented in the paper are valuable to designers of online multiformat-based solutions.