Chargebee logo Chargebee automation · runs weekly

Change a Chargebee subscription plan for customers who ask

A customer asks for the bigger plan mid-month, and someone has to open the subscription, change the plan, choose whether the change applies now or at renewal and work out what the prorated invoice will say.

Cotlet does it in your own Chargebee account with list_subscriptions, get_subscription and change_subscription_plan, called by your AI agent, an n8n workflow or a script.

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Hosted · nothing to install or maintain

Can Chargebee do this on its own?

Chargebee's REST API changes a subscription with update_for_items, including proration and replacing the item list (checked 14 Oct 2026). The ready-made MCP servers cannot change subscriptions. People who want an agent to do it today build a custom MCP server or script and manage an API key themselves.

How you do it in Chargebee today

  1. Open the subscription's details page from the customer profile or the Subscriptions index.
  2. In the Actions pane, click Edit Subscription.
  3. Change the plan, addons or quantities in the form.
  4. In the Apply Changes section, choose Immediately (with an option to apply prorated credits and charges) or During next renewal.
  5. Check old addons by hand: Chargebee does not remove mandatory addons of the old plan unless a site setting says so, and a new scheduled change overrides an earlier one.

How to change a Chargebee subscription plan for customers who ask

Prompt

Move the Chargebee subscription sub_4d7mTz from the Starter plan to Growth now, quantity 1, with proration. Tell me what the invoice will be.
  1. 01

    Confirm the starting plan

    Your agent reads the subscription and compares its current item price with the "from" plan in your prompt. A mismatch, for example a customer already on Growth, ends the job with a one-line report.

  2. 02

    Look for a scheduled change

    Chargebee lets a new scheduled change override an old one. If the subscription already has one, the agent says so before sending anything, so a downgrade planned last month is not overwritten silently.

  3. 03

    Choose timing and proration

    The agent applies the change immediately or at next renewal as you wrote it. It sets proration only when you asked for it, because prorated credits and charges change what the customer sees on the next invoice.

  4. 04

    Handle addons

    If the old plan has mandatory addons that the new plan does not need, the agent lists them and asks, since Chargebee leaves them on the subscription.

  5. 05

    Send it and report the money

    After your OK, change_subscription_plan updates the subscription and returns the invoice the change created, with credit, charge and total, so you can confirm the amounts before the customer opens an email.

What you get back

Example data

Moved sub_4d7mTz from Starter to Growth, effective now, prorated
Invoice INV-1043 created
Credit for unused Starter time: $49.50
Prorated Growth charge: $149.50
Invoice total: $100.00
Next renewal: 2026-11-01

Other ways to ask

  • Downgrade every subscription on the Growth plan whose customer asked in this week's tickets, at next renewal with no proration.
  • Change quantity from 5 to 8 seats on sub_4d7mTz now, prorated, and show me the invoice first.
  • List active Starter subscriptions renewing in the next 7 days so I can pick who to move to Growth.

What Chargebee allows, and what to know first

  • In the Chargebee console the option is Edit Subscription, and Apply Changes offers Immediately, During next renewal and On a specific date; the last one must be enabled by Chargebee Support.
  • A scheduled change can be set up to 1830 days ahead, and a new scheduled change overrides an existing one.
  • With proration on, an immediate change creates credits for unused time and charges for the new time; Chargebee's API proration parameters do not work with scheduled changes.
  • Mandatory addons of the old plan stay on the subscription unless the site setting "Remove mandatory addons from old plan during subscription plan update" is on, and that setting does not apply to the Self-Serve Portal.
  • The update API takes replace_items_list: false adds the items you send to the existing ones, true replaces them.

change_subscription_plan asks for your OK by default. To run it weekly without you, switch confirmation off for that tool in your dashboard.

Sources: Chargebee Docs: Working with Subscriptions · Chargebee API: Update a subscription

Call change_subscription_plan from a script

curl

curl -X PATCH https://cotlet.dev/api/v1/chargebee/item-prices/growth-USD-monthly/subscriptions/sub_4d7mTz/plan \
  -H "Authorization: Bearer $COTLET_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"quantity":1,"apply":"immediately","prorate":true}'

Example response

{
  "subscription": {
    "subscription_id": "sub_4d7mTz",
    "status": "active",
    "items": [
      {
        "item_price_id": "growth-USD-monthly",
        "quantity": 1,
        "unit_price": 29900
      }
    ],
    "next_billing_at": "2026-11-01T00:00:00Z"
  },
  "invoice": {
    "invoice_id": "INV-1043",
    "status": "payment_due",
    "line_items": [
      {
        "description": "Growth plan, prorated charge",
        "amount": 14950
      },
      {
        "description": "Starter plan, unused time credit",
        "amount": -4950
      }
    ],
    "total": 10000,
    "currency_code": "USD"
  }
}

MCP: add https://cotlet.dev/mcp/v1 with the same key; the call is chargebee_write → change_subscription_plan. Example data.

Schedule it in n8n, Make, Zapier or cron

Chargebee tools this automation uses

Cotlet Chargebee tools used to change a Chargebee subscription plan for customers who ask
Tool Parameters
list_subscriptions customer_id, status, item_price_id, next_billing_before, limit, cursor
get_subscription subscription_id
change_subscription_plan subscription_id, item_price_id, quantity, apply, prorate, replace_items
All 12 Chargebee tools with descriptions

Frequently asked questions

Is it safe to connect Chargebee to Cotlet?

Yes. You sign in to Chargebee yourself, in your own Cloud Browser in the EU, and we never save your password. Your agents only get Chargebee once you enable it, every background request is listed, and the browser profile is stored encrypted with AES-256-GCM, the cipher 1Password uses for its vaults. The AI model never sees a login, posts and messages wait for your OK, and Disable for agents cuts access in one click. Independent scanners grade cotlet.dev A+ on Qualys SSL Labs, securityheaders.com and Mozilla Observatory; live results are on https://cotlet.dev/security.

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