Yes, you should include letters of intent in your pitch deck.
In the body of the deck, list the brands that have signed LOIs and an aggregate number for the booked contracts or, if you don’t have that, an aggregate number for the Qualified Pipeline. Make sure this is a big number.
If including the LOIs themselves, add them to the appendix.
At early stage, investors are looking for founder-market fit and for any evidence of customer traction that supports it. For pre-seed companies, investors will take a larger bet on team and opportunity, but by seed stage, investors typically understand the space and how sales cycles work.
Founders need to focus on a story around a repeatable sales model. Pre-sales contracts, LOIs, and MOUs can be part of that story, but they only work if there is a clear path to convert to paid contracts. Unfortunately, a lot of LOIs and MOUs fall through, so investors may regard them with justifiable skepticism.
One way to manage this is to have staged agreements with clear milestones, deliverables and decision gates. Here’s a simple example from Alchemist company Performetry. Note that it specifies the dollar consideration should a final agreement on the transaction be made. Now Performetry can include that figure in its Qualified Pipeline.
Here is a more elaborate example from Betterworks. Note that the agreement automatically renews absent a 30 day written termination notice.
To summarize, pre-sales contracts, LOIs and MOUs are important evidence supporting your product-market fit. To be credible to investors, they must include specific and measurable triggers that convert unpaid engagements into paid engagements.