For a monthly retainer, usually yes. A client who sets up the direct debit while accepting your proposal has agreed how they'll pay as well as what, so the first retainer is collected on its due date instead of waiting for their next payment run. Add a mandate link to the acceptance step, say in the fees section what it covers, and take any upfront payment as a separate step first.
In this article
The short version
- For monthly retainers, putting the mandate in the proposal usually gets the first payment in on time.
- The person who signs may not control the bank account, so make the mandate link easy to forward.
- The fees section should say what the mandate collects, when, and how much notice the client gets.
- The minimum term belongs in the contract, because a mandate is open-ended.
- Take any upfront payment by payment link first, then let the direct debit cover later invoices.
Why the proposal is a good time to ask
A client signs a £2,500 a month retainer on a Thursday and you kick off on Monday. Your first invoice goes out at the end of the month on 30-day terms. It reaches their accounts team, who set you up as a supplier, ask for your bank details on letterhead and pay you on their next run. It's easy for the first payment to arrive the best part of two months after the work started, and by then you've delivered two months of it.
If the mandate is part of accepting the proposal, how you'll be paid is settled in the same step as the price and scope. Each retainer invoice is then collected on its due date, and nobody in your team has to ask.
The person who signs a marketing proposal is often a marketing director or founder, who may not be authorised on the business bank account. Make the mandate link easy to forward, and say in the proposal that whoever looks after the company's bank account can complete it.
What to say in the fees section
A direct debit can collect different amounts under one mandate, as long as the client is told each amount and date in advance. So the fees section doesn't need to fix every figure, but it should say:
- The retainer and the day it's collected.
- That other agreed work, such as extra hours or hosting and software you pass on, is invoiced separately and collected on its due date under the same mandate.
- How much notice the client gets before each collection.
- What happens if a collection fails.
Something like this is enough: "Your retainer of £2,500 + VAT is collected by direct debit on the 1st of each month. Other agreed work is invoiced separately and collected on its due date, and you'll get an email in advance of each collection."
Keep the minimum term and notice period in the contract itself. A mandate is open-ended and either side can cancel it at any time, so it can't hold a client to a twelve-month term, and cancelling it doesn't end what they've agreed to pay.
How to add the mandate and take a first payment
Proposal software usually lets you add a link or button to the acceptance page, the confirmation email or a "next steps" section. Adfin gives you a reusable mandate link that any client can use, so it can sit in your proposal template and you don't need a new link for each client.
If you take the first month upfront, or a deposit before kick-off, treat that as a separate step. Send an invoice with a payment link the client can pay by card, Apple Pay, Google Pay or pay by bank, and let the direct debit cover month two onwards. The client can do both on the day they sign, one after the other.
Some mandates won't be set up by the time the first invoice is due, often because the signer is still waiting on finance. Adfin's AI Customer Agents can send the client a payment link and reminders on the schedule you set, so that invoice can still be paid while the mandate is sorted.
When to leave it out
A mandate in the proposal suits retainers and other regular billing. It's less useful for:
- One-off projects, where a deposit and milestone invoices paid by link usually fit better.
- Larger clients with procurement teams, purchase orders and fixed payment runs, who may not sign direct debits for suppliers at all. Offering bank transfer to bank details unique to that client makes their payments easy to match.
- Clients who tell you they won't pay by direct debit. Agree the alternative in the proposal, so there's still an arrangement in writing.
Common questions
Can one mandate collect the retainer and extra work? Yes. A mandate covers varying amounts, provided the client gets advance notice of each amount and date.
Does a direct debit lock the client into a minimum term? No. Mandates are open-ended and either side can cancel at any time, so the minimum term and notice period belong in your contract.
Who should complete the mandate? Someone authorised on the client's business bank account, which may not be the person who signed the proposal. Make the link easy to forward.
Can I take the first month upfront and then collect by direct debit? Yes, as two steps: a payment link for the first invoice, then the mandate for later ones. The client can complete both on the day they sign.
What if the retainer is very large? Direct debit providers set a limit on each collection, so check yours before the first invoice. Adfin's team can raise its limit on request after a few questions.
What will the client see on their bank statement? Usually a payment provider's name, with a short form of your business name in the reference. Adfin offers a paid option to show your own business name, chosen when you first set up direct debit.
Sources
- Adfin Help Centre - Use the reusable direct debit mandate link to sign up new customers (accurate as of October 2026) https://support.adfin.com/en/articles/13344919-use-the-reusable-direct-debit-mandate-link-to-sign-up-new-customers
- Adfin Help Centre - Getting started with direct debits (accurate as of October 2026) https://support.adfin.com/en/articles/10192945-getting-started-with-direct-debits
- Adfin Help Centre - Can I increase my direct debit payment limit? (accurate as of October 2026) https://support.adfin.com/en/articles/15082246-can-i-increase-my-direct-debit-payment-limit
- Pay.UK (Direct Debit) - The Direct Debit Guarantee (accurate as of October 2026) https://directdebit.co.uk/direct-debit-explained/direct-debit-guarantee/
