SDR vs BDR: What's the Difference and Which Role Does Your Startup Actually Need?

When you're hiring your first or second pipeline generation role, the terminology matters more than you might think — not because the labels are sacred, but because they reveal different assumptions about how your GTM motion works. Hire the wrong type for your current stage and you'll spend six months wondering why pipeline isn't building the way you expected.

The textbook definition

SDR (Sales Development Representative) — typically focused on inbound lead qualification. They receive leads generated by marketing — content downloads, webinar sign-ups, demo requests — and qualify them before passing to AEs. Their metric is qualified meetings passed to pipeline.

BDR (Business Development Representative) — typically focused on outbound prospecting. They identify target accounts, build contact lists, write and send sequences, and cold-call. No warm lead to work from. Their job is to create pipeline where none existed.

In practice, many UK SaaS companies use the terms interchangeably, which causes confusion in briefs and misaligned hires.

Which one does your startup actually need?

Ask yourself one question: where does your current pipeline come from?

If more than 60% of your deals start with inbound — someone found you, requested a demo, or came through a partner referral — you have a demand generation engine that needs qualifying. You need an SDR to handle volume and speed up response times.

If you're mostly winning deals through founder-led outbound, referrals, or your own network, and you want to scale that motion, you need a BDR. Someone who can systematically identify, sequence, and engage cold accounts at volume.

The mistake early-stage founders make is hiring an SDR to do outbound work — then wondering why pipeline isn't growing. SDRs who've only ever worked inbound queues often struggle to build cadences from scratch, write compelling cold copy, and handle the rejection rate that outbound requires.

What does "good" look like at seed stage?

At seed, you usually can't afford to hire separately for both functions. The question becomes: what's your primary acquisition motion?

If you're going outbound-first, hire someone who has demonstrated success building pipeline from cold. Ask to see their sequence data — open rates, reply rates, meeting booked rates. Good outbound people track this obsessively. If they can't show you numbers, they haven't been doing real outbound.

If you're inbound-led, hire someone fast, organised, and commercially curious. Speed-to-lead matters enormously — research consistently shows that responding to an inbound demo request within 5 minutes increases conversion by 8x compared to responding after an hour. Your SDR needs to be the person who makes that happen.

Writing the brief correctly

The biggest brief mistake we see: writing "SDR/BDR" as if they're the same thing. Be explicit about what you need:

• What percentage of their time will be outbound vs inbound qualification?
• Do they have a sequence tool (Outreach, Salesloft, Apollo) or will they be building from scratch in a basic CRM?
• What does success look like at 90 days? Meetings booked or qualified meetings passed?
• Who writes the sequences — them or marketing? (A strong BDR wants to write their own.)

Get these answers nailed before the role goes to market. The candidate who thrives in a fully outbound environment is a genuinely different person from the one who thrives qualifying a warm inbound queue. A precise brief finds the right one faster.