Add a direct debit step to the proposal or engagement letter itself, so your client agrees the fee and signs the mandate in the same sitting. Socket, Engager.app and Sodium can all do this with Adfin, and once the mandate is live the first fee is collected on its due date without a separate request or a chase.
In this article
The short version
- Put the direct debit step inside the proposal or engagement letter so fee and mandate are agreed together
- Socket, Engager.app and Sodium can all capture the mandate with Adfin as the client signs
- One mandate covers varying amounts, as long as the client gets notice before each collection
- The letter should say what the mandate covers, when collections happen, the notice period and what happens if one fails
- If a client can't sign in the meeting, send the request straight after; Adfin keeps reminding them
Why mandates go unsigned after the proposal
The usual sequence goes like this. Your client signs the proposal or engagement letter, and a day or two later someone sends the direct debit link in a separate email that reads like admin. Plenty come back quickly. The rest sit there, and by the first invoice run you've got three groups of clients: on direct debit, paying by hand, and agreed to your fee but not yet collectable.
Your client agreed the fee in writing, but how the money would reach you was left for later, and the moment they sign tends to be when they're most willing to do the next small thing you ask. Two days later, your mandate email is competing with everything else in their inbox.
Putting the mandate inside the signing step closes that gap. There's no list of unsigned mandates to keep track of, and your team only deals with exceptions: the client who can't find their sort code, or the one whose bank needs two signatures.
How it works in Socket, Engager.app and Sodium
The proposal tool holds the price, the scope and the signature. The payment provider holds the mandate and collects the money. With Adfin connected, your client fills in a short form as part of accepting: account name, sort code, account number, and confirmation of the mandate terms.
- Socket: your client reaches the fee summary and sets up the direct debit before they can sign, then comes back to accept the proposal. Clients who already pay you by direct debit are recognised and skip the step, and you can switch it off for an individual client.
- Engager.app: you set direct debit as mandatory, optional or not offered by default, and change it on any letter. After signing, your client is prompted to set up the direct debit before approving the engagement, and you can track each mandate's status from Engager.
- Sodium: direct debit setup can sit inside the proposal acceptance flow, and you can map existing mandates to clients in bulk from one screen.
Once the mandate is signed, invoices you raise for that client are collected on their due date. Their bank usually activates a new mandate within three working days, your client is notified at least three working days before each collection, and Adfin pays the money out to you in full within three working days of the collection date, with its fee invoiced separately. Signing at proposal stage doesn't make any of those steps quicker, but the clock starts on the day your client says yes, not when they get round to a follow-up email.
What to put in the proposal or letter
A direct debit can collect different amounts under one mandate, as long as your client is told the amount and date in advance. So you don't need a fixed figure, but you do need to say what you'll collect and when. The letter should cover:
- What the mandate covers: the monthly fee, ad hoc work, disbursements, the year-end balance.
- When collections happen, for example on each invoice's due date.
- How much notice your client gets before each collection. The Direct Debit Guarantee tells payers they'll normally get 10 working days' notice of a change unless something else is agreed, and you can agree a shorter period in the letter. Adfin gives at least three working days' notice, so state the period you'll use and keep to it.
- What happens if a collection fails.
It also helps to mention direct debit in the fee conversation, before the letter goes out. One sentence like "we collect fees by direct debit on the due date, and you'll get notice before each one" is easier than a paragraph of explanation after the fact, and it means the bank details step doesn't come as a surprise.
When a client can't sign in the meeting
Some clients won't, often for good reasons. The person in the room may not be authorised on the business bank account, or the account needs two signatures. Pushing tends to backfire. In Engager you can make the step optional on that letter, and in Socket you can switch it off for that client, then send the mandate request straight afterwards while the conversation is fresh.
That request still needs following up. If the mandate isn't signed when the first invoice goes out, Adfin keeps reminding your client automatically and offers them another way to pay in the meantime. Where the bank account needs more than one signatory, your client completes the online form and then sends back a printed copy signed by the others.
After that, Adfin's Customer Agents handle what follows within rules you set: reminders on your schedule by email, SMS or WhatsApp, free retries if a direct debit fails, and a request to pay another way if the retries don't work.
Common questions
Which proposal tools work with Adfin for direct debit? Socket, Engager.app and Sodium. Each can include the direct debit step in signing, and Adfin then collects and syncs payments back to Xero or QuickBooks.
Is it better to take bank details before or after the client signs? Before signature, the mandate is part of accepting your fee, so there's nothing to chase afterwards. After signature suits clients who need someone else to authorise the bank account.
Does a direct debit work if my fee changes each month? Yes. One mandate covers varying amounts, as long as your client gets advance notice of each amount and date.
How long until the first collection? The client's bank usually activates the mandate within three working days, and the first collection is taken on the invoice due date after at least three working days' notice.
Do I need my own Service User Number? Not with Adfin. Collections run under Adfin's, and Adfin's name shows on statements unless you choose Adfin Custom at onboarding for £36 a month.
What about clients already paying by direct debit with another provider? If you have 10 or more mandates, they move to Adfin through the Bacs bulk change process and your clients don't re-sign. With fewer than 10, clients sign a new Adfin mandate.
Sources
- Adfin - Adfin for Socket (accurate as of October 2026) https://www.adfin.com/integrations/socket
- Adfin Help Centre - Get started with Adfin payments in Engager (accurate as of October 2026) https://support.adfin.com/en/articles/11991654-get-started-with-adfin-payments-in-engager
- Socket Help Centre - Moving your Socket clients to Adfin for payments (accurate as of October 2026) https://help.usesocket.com/en/articles/11750362-moving-your-socket-clients-to-adfin-for-payments
- Sodium - Integrations (accurate as of October 2026) https://sodiumhq.com/features/integrations
- 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
- Direct Debit - The Direct Debit Guarantee (accurate as of October 2026) https://www.directdebit.co.uk/direct-debit-guarantee/
