Your accountant is not working for you: switch to BMC without disrupting anything, and with a free tax audit

68% of self-employed professionals and SMEs that switch accountants do so because they have been tolerating, for months (sometimes years), situations they should not have to tolerate: responses that take days or weeks, returns filed with errors that generate additional assessments and surcharges, no proactive call when the regulations affecting them change, and the feeling that their accountant manages their obligations from the past but never thinks about their fiscal future. Many keep putting up with it because they believe that changing adviser is complicated, risky or expensive. It is not. The greatest cost of staying with an accountant that is not working is not the time lost on unanswered calls. It is the opportunity cost: the deductions nobody has explained to you, the corporate structure that was never optimised, the VAT regime that is not the most appropriate for your activity, the deductible expenses that are not being applied correctly. A reactive accountant that simply files what you give them when you give it is not an adviser: it is a tax typing service that costs the same as a real adviser.

Since 2010 · 16 years Tax agent AEAT

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Why BM Consulting

Specialised advice and personal service

BMC manages the complete transition with virtually no effort on your part. We contact your previous accountant directly to request the necessary documentation, centralise all your tax data, review the returns from the past four years looking for errors or improvements, and take over your tax obligations without any break in continuity. There is no risk of missing any deadline during the transition: we coordinate so that the switch is invisible both to the AEAT and to you. The first month includes a full tax audit of your situation: we review the applicable tax regime, deductible expenses that are not being taken advantage of, the structure of your activity and any tax contingency your previous accountant may have created without telling you. This audit has revealed savings or contingencies that the client was unaware of in 60% of cases. The switch not only improves the service: it typically also improves your tax bill.

  • Switching accountants mid-year is entirely possible. BMC manages the full documentation migration without interrupting service.

  • The handover audit detects errors or non-compliance from the previous period, correcting them before an inspection.

  • Accounting migration can take place at any point in the year, even during a VAT or income tax filing campaign.

  • The most common errors found when switching accountants

    miscalculated depreciation, IVA incorrectly deducted and payroll with incorrect employment categories.

How we work

From first contact to case completion

  1. Free audit of your current tax position

    We ask for your most recent returns and meet, in person or by video call, to review your current situation. We identify errors in past returns, untapped tax opportunities and potential contingencies generated by incorrect filings. This audit is free and without any commitment.

  2. Coordination with your previous accountant

    We take care of requesting from your previous accountant all the documentation needed for the transition: accounting books, filed returns, AEAT returns, census information and any open case. You do not need to manage any awkward conversation with your previous adviser.

  3. Data migration and service continuity

    We integrate all received information into our platform and take over your tax obligations with no gap in coverage. We verify that all census data with the AEAT is correct, review direct debits and filing calendars, and make sure no deadline is at risk during the switch.

  4. Onboarding and first full year

    We introduce you to your assigned adviser at BMC, who has a thorough knowledge of your situation from day one. We explain what information we need from you and how you prefer to work, and we establish the communication rhythm. From the first quarter we manage your obligations to the quality, proactivity and response-time standards that BMC guarantees.

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The problem

68% of self-employed professionals and SMEs that switch accountants do so because they have been tolerating, for months (sometimes years), situations they should not have to tolerate: responses that take days or weeks, returns filed with errors that generate additional assessments and surcharges, no proactive call when the regulations affecting them change, and the feeling that their accountant manages their obligations from the past but never thinks about their fiscal future. Many keep putting up with it because they believe that changing adviser is complicated, risky or expensive. It is not. The greatest cost of staying with an accountant that is not working is not the time lost on unanswered calls. It is the opportunity cost: the deductions nobody has explained to you, the corporate structure that was never optimised, the VAT regime that is not the most appropriate for your activity, the deductible expenses that are not being applied correctly. A reactive accountant that simply files what you give them when you give it is not an adviser: it is a tax typing service that costs the same as a real adviser.

Our solution

BMC manages the complete transition with virtually no effort on your part. We contact your previous accountant directly to request the necessary documentation, centralise all your tax data, review the returns from the past four years looking for errors or improvements, and take over your tax obligations without any break in continuity. There is no risk of missing any deadline during the transition: we coordinate so that the switch is invisible both to the AEAT and to you. The first month includes a full tax audit of your situation: we review the applicable tax regime, deductible expenses that are not being taken advantage of, the structure of your activity and any tax contingency your previous accountant may have created without telling you. This audit has revealed savings or contingencies that the client was unaware of in 60% of cases. The switch not only improves the service: it typically also improves your tax bill.

Process

How we do it

1

Free audit of your current tax position

We ask for your most recent returns and meet, in person or by video call, to review your current situation. We identify errors in past returns, untapped tax opportunities and potential contingencies generated by incorrect filings. This audit is free and without any commitment.

2

Coordination with your previous accountant

We take care of requesting from your previous accountant all the documentation needed for the transition: accounting books, filed returns, AEAT returns, census information and any open case. You do not need to manage any awkward conversation with your previous adviser.

3

Data migration and service continuity

We integrate all received information into our platform and take over your tax obligations with no gap in coverage. We verify that all census data with the AEAT is correct, review direct debits and filing calendars, and make sure no deadline is at risk during the switch.

4

Onboarding and first full year

We introduce you to your assigned adviser at BMC, who has a thorough knowledge of your situation from day one. We explain what information we need from you and how you prefer to work, and we establish the communication rhythm. From the first quarter we manage your obligations to the quality, proactivity and response-time standards that BMC guarantees.

0€
Cost of migration from your previous accountant
<24h
Guaranteed response time to queries
15%
Average tax saving found in switch audits

I had been with the same accountant for three years and they never called about anything. I found out about the R&D deduction for my software development activity through an internet article, not from my adviser. BMC reviewed my last four returns and found I could reclaim 8,400 euros in unclaimed deductions. The switch paid for itself in the first year.

Diego Mora Casas Self-employed developer, Freelance, Valencia

Signs that your current accountant is not working for you

There is a fundamental difference between an accountant that manages tax obligations and an adviser who works actively to optimise the client’s tax position. Many self-employed professionals and SMEs pay for the second and receive only the first. These are the clearest signs that it is time to switch:

  • Returns are filed without any prior discussion. Nobody called to check whether there were extraordinary expenses, new investments or changes in activity that quarter. The return simply appears.
  • Responses take days, sometimes weeks. A query about whether an expense is deductible should not wait four working days. If it does, the firm is managing a volume of clients that does not allow them to serve you well.
  • Nobody tells you about regulatory changes that affect you. You find out through a press article that the withholding rate for your sector has changed, or that there is a new deduction for your activity, without your adviser having said a word.
  • You have received additional assessments or surcharges for incorrect returns. Errors in tax returns have consequences that are paid with interest and surcharges. An accountant that makes errors costs you more than they charge.
  • The adviser who signed the contract has not picked up the phone for some time. Whoever is available attends to you, with no real knowledge of your situation.

The real cost of an accountant that is not working is not the monthly fee: it is the accumulated opportunity cost of unclaimed deductions, suboptimal tax regimes and structures that have never been reviewed.

How to switch accountants step by step: no penalty, no lock-in period

Switching accountants is a right, not a complicated procedure. There is no lock-in period and no penalty under tax law (subject to any contractual minimum-term clauses, which are worth checking). The AEAT neither penalises nor flags in any way a taxpayer who changes their representative.

The process has four steps:

  1. You decide to switch and contact the new firm. The first meeting is used to review your current situation and identify any imminent deadlines to manage during the transition.
  2. The new firm requests documentation from the previous one. Returns from the past four years, accounting books, census data, and access credentials to the AEAT and TGSS. This documentation always belongs to the client. If the previous accountant resists, the new firm manages this directly.
  3. You sign the representation authorisation with the AEAT. The client authorises the new firm to represent them. It is an electronic procedure that takes minutes.
  4. The new firm takes over the obligations without any gap. The ideal moment is the start of a quarter, although a well-managed transition leaves no deadline unattended at any point in the year.

What documentation to recover from your previous accountant

The documentation you need before or during the switch:

  • Returns filed for the past four years (Modelos 303, 130, 100, 390, 347, 349 as applicable)
  • IVA Register Books (invoices issued and received) in electronic format
  • Official accounting records if you are a company (journal, ledger, balance sheets)
  • Access credentials to the AEAT portal and the TGSS
  • Status of any ongoing inspection or appeal case

When to switch: The start of a quarter (January, April, July, October) is the ideal time. Switching during the income tax campaign (April-June) or in the week that a quarterly deadline closes adds unnecessary complexity. If the situation is urgent, the switch can take place at any time.

What to ask your new accountant before signing

Not all accounting firms are alike. Before signing it is worth knowing:

  • Who will handle my file? Will there be a dedicated adviser or will it rotate?
  • What is the guaranteed response time for queries?
  • Do I have access to a portal to consult my returns and documentation?
  • What is included in the monthly fee and what has an additional cost?
  • How will I be informed of regulatory changes that affect me?

Indicative ranges for 2026: self-employed professionals without employees, between 60 and 150 euros per month depending on complexity; SMEs with full accounting and payroll, between 200 and 500 euros per month. Firms that charge significantly below these ranges typically compensate with slow response times or client portfolios so large that personalised attention is impossible.

BMC’s free audit: what we review and what we typically find

The first meeting with BMC is not a sales presentation: it is a real tax review of your situation. We analyse the most recent four returns available and review:

  • The IRPF estimation regime and whether it is the most efficient for your actual income and expenditure levels
  • The VAT regime applied and whether there is a better alternative (prorata, simplified regime, retail equivalence surcharge)
  • The deductible expenses that have been applied and those that have not been, but could be (subsistence allowances, vehicle, home office, professional insurance, subscriptions)
  • Whether the current structure, self-employed, company or group, is optimal from a tax perspective
  • Latent tax contingencies generated by previous incorrect returns

In switch audits carried out over the past 12 months, BMC has found an average of 15% tax saving compared with the previous position. The most frequent findings are unclaimed deductible expenses, unclaimed tax credits (R&D in software, new technologies) and incorrect VAT regimes for mixed or intra-Community activities.

Tax contingencies your previous accountant may have generated

The handover audit is not only a search for future improvements: it is also a review of past risks. The most common tax contingencies we find when clients switch accountants are:

Non-deductible expenses incorrectly applied. Personal expenses of a partner charged to the company, remuneration to partners without a formal employment contract, household utility expenses that do not meet the Tax Agency’s requirements for home-office activity. If these expenses have generated IVA deducted or Corporate Tax bases reduced incorrectly, there is a contingency in the event of an inspection.

IVA deducted without documentary support. Article 97 of the Ley del IVA requires that the deduction be supported by a complete invoice. IVA deducted on till receipts, invoices with incomplete details or invoices for non-existent transactions is a serious contingency that the AEAT detects in formal reviews of the received invoice register.

Withholdings not applied on payments to professional service providers. The 15% withholding on invoices from self-employed professionals is mandatory where the recipient carries on economic activities under direct estimation. The absence of withholding on professional service invoices paid to self-employed professionals generates a debt of the withholding agent (the company) with the tax authorities, with interest and possible penalties.

Incorrectly calculated depreciation. Fixed asset items must be depreciated at the maximum rates from the Corporate Tax or IRPF depreciation tables. Excess depreciation generates a taxable base lower than the correct one; insufficient depreciation generates a deferred tax asset yet to be applied. In both cases, regularisation has consequences and requires a review of the accounting useful life of each asset.

Late filings not communicated. The previous accountant may have filed returns after the legal deadline, with automatic surcharges of 5%, 10%, 15% or 20% depending on the delay, without telling the client. A review of the filing history on the AEAT’s electronic seat can reveal late filings and their associated surcharges.

From a legal perspective, switching accountants involves principally two actions with the AEAT:

Revocation of the previous representation. The client must revoke the representation previously granted to the previous accountant to act before the AEAT. This revocation can be done directly on the AEAT’s electronic seat using a digital certificate or Cl@ve, or can be managed by the new firm once it has been authorised.

New representation granted to BMC. The client grants BMC the authority to act before the AEAT on their behalf: filing returns, accessing electronic notifications, checking the status of cases and representation in audit proceedings. The representation is formalised on the AEAT’s electronic seat and takes effect immediately.

It is not necessary to notify the AEAT of the change of representative separately: revoking the previous authorisation and granting the new one are sufficient. The AEAT has no restriction and imposes no waiting period for a change of representative.

Why entrust the switch to BMC rather than managing it yourself

A well-executed switch of accountants should be invisible to the client: deadlines are met, documentation is transferred, and the first quarter with the new firm passes without incident. What distinguishes BMC is not only the ability to execute that transition, but what happens afterwards.

BMC guarantees by contract a response time of less than 24 working hours to any query. It has a proactive tax review process that generates alerts when the regulations applicable to each client change. Each client has a dedicated adviser with a full picture of their situation, with access to BMC’s specialist team for matters of international taxation, corporate transactions or inspections. The first-month audit, free and without commitment, has value in itself regardless of whether you decide to continue. And if BMC finds in that audit that your current situation is well managed, we will say so.

FAQ

Frequently asked questions

The process is simpler than most clients anticipate. Once you decide to switch, BMC contacts your previous accountant to request all the documentation we need: accounting books, filed returns, status of open cases and census data. You sign the representation documents authorising BMC to act on your behalf before the AEAT, and we manage everything else. The full transition process is usually completed in one or two weeks, with no deadline left unattended.
No. The transition is planned precisely so that there is no interruption. We identify all pending filing deadlines and coordinate so that the switch takes place without leaving any of them unattended. In cases where the switch coincides with an imminent deadline (a VAT quarter, an income tax return), we manage that deadline within the transition process to ensure it is filed on time and in the correct form.
We need the returns filed for the past four years (the standard tax limitation period), the accounting books in electronic format where available, the settlement of periodic returns for the current year, the updated Business and Professionals Census data, and any inspection or appeal case that is currently open. In most cases, the previous accountant is required to provide this documentation to the client, as it belongs to the client, although they sometimes resist, a situation that BMC manages directly.
It is more common than it might appear. During the initial audit, we analyse the returns from the past four years to identify any errors that may have been made: expenses not deducted that should have been, incorrect taxable bases, VAT regimes incorrectly applied, omitted deductions. If we find errors that were to your detriment, we manage the filing of supplementary returns or rectification requests to recover what you are owed. If we find errors that incorrectly benefited you (which also happens), we inform you of the risk and advise on voluntary regularisation, which is always more favourable than regularisation following an inspection.
The standard transition process, from the first audit meeting to BMC having taken full responsibility for all the client's tax obligations, takes between two and four weeks. Factors that may extend this period are resistance from the previous accountant in handing over documentation (infrequent but it does happen) and the complexity of the client's tax situation (groups of companies, activities under multiple VAT regimes, ongoing inspection cases). For standard situations (self-employed professional or small-to-medium company with no particular complications), two weeks is a comfortable timeframe.
The first-month audit is a full review of the client's tax situation covering: the estimation regime (simplified direct, standard direct or objective in IRPF) and whether it is the most appropriate for your actual income and expenditure levels; the VAT regime applied (general, simplified, retail equivalence surcharge, prorata) and whether it is the correct one for your activity; the deductible expenses that have been applied and those that have not been applied but could be; an analysis of whether the current structure (self-employed vs. company, or between different corporate forms) is optimal from a tax perspective; and a review of any open or latent tax contingency. The result is delivered in a written report with specific recommendations and quantified amounts where possible.

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Frequently asked questions

Questions about Switch Accountant to BMC: Free Migration and Audit

The process is simpler than most clients anticipate. Once you decide to switch, BMC contacts your previous accountant to request all the documentation we need: accounting books, filed returns, status of open cases and census data. You sign the representation documents authorising BMC to act on your behalf before the AEAT, and we manage everything else. The full transition process is usually completed in one or two weeks, with no deadline left unattended.
No. The transition is planned precisely so that there is no interruption. We identify all pending filing deadlines and coordinate so that the switch takes place without leaving any of them unattended. In cases where the switch coincides with an imminent deadline (a VAT quarter, an income tax return), we manage that deadline within the transition process to ensure it is filed on time and in the correct form.
We need the returns filed for the past four years (the standard tax limitation period), the accounting books in electronic format where available, the settlement of periodic returns for the current year, the updated Business and Professionals Census data, and any inspection or appeal case that is currently open. In most cases, the previous accountant is required to provide this documentation to the client, as it belongs to the client, although they sometimes resist, a situation that BMC manages directly.
It is more common than it might appear. During the initial audit, we analyse the returns from the past four years to identify any errors that may have been made: expenses not deducted that should have been, incorrect taxable bases, VAT regimes incorrectly applied, omitted deductions. If we find errors that were to your detriment, we manage the filing of supplementary returns or rectification requests to recover what you are owed. If we find errors that incorrectly benefited you (which also happens), we inform you of the risk and advise on voluntary regularisation, which is always more favourable than regularisation following an inspection.
The standard transition process, from the first audit meeting to BMC having taken full responsibility for all the client's tax obligations, takes between two and four weeks. Factors that may extend this period are resistance from the previous accountant in handing over documentation (infrequent but it does happen) and the complexity of the client's tax situation (groups of companies, activities under multiple VAT regimes, ongoing inspection cases). For standard situations (self-employed professional or small-to-medium company with no particular complications), two weeks is a comfortable timeframe.
The first-month audit is a full review of the client's tax situation covering: the estimation regime (simplified direct, standard direct or objective in IRPF) and whether it is the most appropriate for your actual income and expenditure levels; the VAT regime applied (general, simplified, retail equivalence surcharge, prorata) and whether it is the correct one for your activity; the deductible expenses that have been applied and those that have not been applied but could be; an analysis of whether the current structure (self-employed vs. company, or between different corporate forms) is optimal from a tax perspective; and a review of any open or latent tax contingency. The result is delivered in a written report with specific recommendations and quantified amounts where possible.
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